51715555521 has 32 divisors (see below), whose sum is σ = 80237058048. Its totient is φ = 29017422720.

The previous prime is 51715555513. The next prime is 51715555571. The reversal of 51715555521 is 12555551715.

It is not a de Polignac number, because 51715555521 - 2³ = 51715555513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51715555511) 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, 381676 + ... + 499106.

It is an arithmetic number, because the mean of its divisors is an integer number (2507408064).

Almost surely, 2^51715555521 is an apocalyptic number.

It is an amenable number.

51715555521 is a deficient number, since it is larger than the sum of its proper divisors (28521502527).

51715555521 is a wasteful number, since it uses less digits than its factorization.

51715555521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117821.

The product of its digits is 218750, while the sum is 42.

The spelling of 51715555521 in words is "fifty-one billion, seven hundred fifteen million, five hundred fifty-five thousand, five hundred twenty-one".