51500865 has 32 divisors (see below), whose sum is σ = 89591040. Its totient is φ = 25111296.

The previous prime is 51500863. The next prime is 51500881. The reversal of 51500865 is 56800515.

It is a happy number.

It is not a de Polignac number, because 51500865 - 2¹ = 51500863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51500863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20044 + ... + 22466.

It is an arithmetic number, because the mean of its divisors is an integer number (2799720).

Almost surely, 2^51500865 is an apocalyptic number.

It is an amenable number.

51500865 is a deficient number, since it is larger than the sum of its proper divisors (38090175).

51500865 is a wasteful number, since it uses less digits than its factorization.

51500865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2553.

The product of its (nonzero) digits is 6000, while the sum is 30.

The square root of 51500865 is about 7176.4103143563. The cubic root of 51500865 is about 372.0530260288.

The spelling of 51500865 in words is "fifty-one million, five hundred thousand, eight hundred sixty-five".