51020520521 has 2 divisors, whose sum is σ = 51020520522. Its totient is φ = 51020520520.

The previous prime is 51020520493. The next prime is 51020520527. The reversal of 51020520521 is 12502502015.

51020520521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39569166400 + 11451354121 = 198920^2 + 107011^2 .

It is a cyclic number.

It is not a de Polignac number, because 51020520521 - 2²⁶ = 50953411657 is a prime.

It is a super-2 number, since 2×51020520521² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51020520527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25510260260 + 25510260261.

It is an arithmetic number, because the mean of its divisors is an integer number (25510260261).

Almost surely, 2^51020520521 is an apocalyptic number.

It is an amenable number.

51020520521 is a deficient number, since it is larger than the sum of its proper divisors (1).

51020520521 is an equidigital number, since it uses as much as digits as its factorization.

51020520521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1000, while the sum is 23.

The spelling of 51020520521 in words is "fifty-one billion, twenty million, five hundred twenty thousand, five hundred twenty-one".