51515165 has 16 divisors (see below), whose sum is σ = 68871600. Its totient is φ = 36728832.

The previous prime is 51515159. The next prime is 51515209. The reversal of 51515165 is 56151515.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 3545689 + 47969476 = 1883^2 + 6926^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51515165 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11780 + ... + 15549.

It is an arithmetic number, because the mean of its divisors is an integer number (4304475).

Almost surely, 2^51515165 is an apocalyptic number.

It is an amenable number.

51515165 is a deficient number, since it is larger than the sum of its proper divisors (17356435).

51515165 is a wasteful number, since it uses less digits than its factorization.

51515165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27376.

The product of its digits is 3750, while the sum is 29.

The square root of 51515165 is about 7177.4065650484. The cubic root of 51515165 is about 372.0874582397.

The spelling of 51515165 in words is "fifty-one million, five hundred fifteen thousand, one hundred sixty-five".