51115665 has 16 divisors (see below), whose sum is σ = 81936000. Its totient is φ = 27211392.

The previous prime is 51115657. The next prime is 51115679. The reversal of 51115665 is 56651115.

It is not a de Polignac number, because 51115665 - 2³ = 51115657 is a prime.

It is a super-2 number, since 2×51115665² = 5225622416784450, which contains 22 as substring.

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, 6141 + ... + 11829.

It is an arithmetic number, because the mean of its divisors is an integer number (5121000).

Almost surely, 2^51115665 is an apocalyptic number.

It is an amenable number.

51115665 is a deficient number, since it is larger than the sum of its proper divisors (30820335).

51115665 is a wasteful number, since it uses less digits than its factorization.

51115665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6296.

The product of its digits is 4500, while the sum is 30.

The square root of 51115665 is about 7149.5220119949. The cubic root of 51115665 is about 371.1231152733.

The spelling of 51115665 in words is "fifty-one million, one hundred fifteen thousand, six hundred sixty-five".