51687850521 has 64 divisors (see below), whose sum is σ = 73863901440. Its totient is φ = 32102645760.

The previous prime is 51687850519. The next prime is 51687850561. The reversal of 51687850521 is 12505878615.

It is not a de Polignac number, because 51687850521 - 2¹ = 51687850519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51687850561) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 72902115 + ... + 72902823.

It is an arithmetic number, because the mean of its divisors is an integer number (1154123460).

Almost surely, 2^51687850521 is an apocalyptic number.

It is an amenable number.

51687850521 is a deficient number, since it is larger than the sum of its proper divisors (22176050919).

51687850521 is a wasteful number, since it uses less digits than its factorization.

51687850521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066.

The product of its (nonzero) digits is 672000, while the sum is 48.

The spelling of 51687850521 in words is "fifty-one billion, six hundred eighty-seven million, eight hundred fifty thousand, five hundred twenty-one".