15

Previous number

14

Next number

16

Sum of digits

6

Divisors of 15

Number of divisors

4

Sum of divisors

24

Factorization

15 = 3 × 5

Prime factors of 15

Factor Count
3 1
5 1

Square of 15

225

Cube of 15

3375

Square root of 15

3.87298334620741702138957407441922...

Cube root of 15

2.46621207433046985002533801889513...

15th triangle number

120

Reciprocal of 15

0.0666666666666667

Binary of 15

1111

Number of digits of 15 in base 2

4

Octal of 15

17

Hexadecimal of 15

f

Prime number No
Hexagonal number Yes
Perfect number No
Deficient number No
Abundant number No
Mersenne number Yes
Harshad number No
Harmonic divisor number No

Quadratic residues of 15

QR15 (sequence)

15th composite number

25

Euler's totient function of 15

8

Carmichael function of 15

4

Möbius function of 15

1

Properties of 15

Properties of the number 15: 15 has 4 divisors. The divisors of 15 are 1, 3, 5, 15 and the sum of them is 24. The factorization of 15 is 3 × 5. The square and cube of 15 are 225 and 3375 respectively. The square root and cube root of 15 are 3.87298334620741702138957407441922... and 2.46621207433046985002533801889513.... The binary, octal, hexadecimal of 15 are 1111, 17, f. 15 is not a prime number, hexagonal number, not perfect number, not deficient number, not Mersenne number, Mersenne number, not Harshad number, not harmonic divisor number.

sin 15

0.65028784015711682542359994840808...

cos 15

-0.75968791285882131258944127694122...

tan 15

-0.85599340090851872009380940653500...

sin 15°

0.25881904510252073947640383266844...

cos 15°

0.96592582628906831221371476203785...

tan 15°

0.26794919243112269580109341404750...

log 15

2.70805020110221006390816000930499...

log10 15

1.17609125905568134839995764195919...

log2 15

3.90689059560851870145370412501507...

Related pairs