51731004581 has 2 divisors, whose sum is σ = 51731004582. Its totient is φ = 51731004580.

The previous prime is 51731004541. The next prime is 51731004643. The reversal of 51731004581 is 18540013715.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36956602081 + 14774402500 = 192241^2 + 121550^2 .

It is a cyclic number.

It is not a de Polignac number, because 51731004581 - 2³⁴ = 34551135397 is a prime.

It is a super-2 number, since 2×51731004581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51731004541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25865502290 + 25865502291.

It is an arithmetic number, because the mean of its divisors is an integer number (25865502291).

Almost surely, 2^51731004581 is an apocalyptic number.

It is an amenable number.

51731004581 is a deficient number, since it is larger than the sum of its proper divisors (1).

51731004581 is an equidigital number, since it uses as much as digits as its factorization.

51731004581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 35.

The spelling of 51731004581 in words is "fifty-one billion, seven hundred thirty-one million, four thousand, five hundred eighty-one".