51561015013 has 2 divisors, whose sum is σ = 51561015014. Its totient is φ = 51561015012.

The previous prime is 51561014993. The next prime is 51561015089. The reversal of 51561015013 is 31051016515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50507168644 + 1053846369 = 224738^2 + 32463^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51561015013 is a prime.

It is a super-2 number, since 2×51561015013² (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 (51561615013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25780507506 + 25780507507.

It is an arithmetic number, because the mean of its divisors is an integer number (25780507507).

Almost surely, 2^51561015013 is an apocalyptic number.

It is an amenable number.

51561015013 is a deficient number, since it is larger than the sum of its proper divisors (1).

51561015013 is an equidigital number, since it uses as much as digits as its factorization.

51561015013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2250, while the sum is 28.

The spelling of 51561015013 in words is "fifty-one billion, five hundred sixty-one million, fifteen thousand, thirteen".