51521075021 has 16 divisors (see below), whose sum is σ = 56240869440. Its totient is φ = 46913368320.

The previous prime is 51521075009. The next prime is 51521075027. The reversal of 51521075021 is 12057012515.

It is not a de Polignac number, because 51521075021 - 2³⁰ = 50447333197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51521075027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 226850 + ... + 393068.

It is an arithmetic number, because the mean of its divisors is an integer number (3515054340).

Almost surely, 2^51521075021 is an apocalyptic number.

It is an amenable number.

51521075021 is a deficient number, since it is larger than the sum of its proper divisors (4719794419).

51521075021 is a wasteful number, since it uses less digits than its factorization.

51521075021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166556.

The product of its (nonzero) digits is 3500, while the sum is 29.

Adding to 51521075021 its reverse (12057012515), we get a palindrome (63578087536).

The spelling of 51521075021 in words is "fifty-one billion, five hundred twenty-one million, seventy-five thousand, twenty-one".