51331528021 has 2 divisors, whose sum is σ = 51331528022. Its totient is φ = 51331528020.

The previous prime is 51331528009. The next prime is 51331528057. The reversal of 51331528021 is 12082513315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50476608900 + 854919121 = 224670^2 + 29239^2 .

It is a cyclic number.

It is not a de Polignac number, because 51331528021 - 2¹⁵ = 51331495253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51331528321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25665764010 + 25665764011.

It is an arithmetic number, because the mean of its divisors is an integer number (25665764011).

Almost surely, 2^51331528021 is an apocalyptic number.

It is an amenable number.

51331528021 is a deficient number, since it is larger than the sum of its proper divisors (1).

51331528021 is an equidigital number, since it uses as much as digits as its factorization.

51331528021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 31.

The spelling of 51331528021 in words is "fifty-one billion, three hundred thirty-one million, five hundred twenty-eight thousand, twenty-one".