51256156513 has 2 divisors, whose sum is σ = 51256156514. Its totient is φ = 51256156512.

The previous prime is 51256156481. The next prime is 51256156541. The reversal of 51256156513 is 31565165215.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31354847329 + 19901309184 = 177073^2 + 141072^2 .

It is a cyclic number.

It is not a de Polignac number, because 51256156513 - 2⁵ = 51256156481 is a prime.

It is not a weakly prime, because it can be changed into another prime (51256156313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25628078256 + 25628078257.

It is an arithmetic number, because the mean of its divisors is an integer number (25628078257).

Almost surely, 2^51256156513 is an apocalyptic number.

It is an amenable number.

51256156513 is a deficient number, since it is larger than the sum of its proper divisors (1).

51256156513 is an equidigital number, since it uses as much as digits as its factorization.

51256156513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 135000, while the sum is 40.

The spelling of 51256156513 in words is "fifty-one billion, two hundred fifty-six million, one hundred fifty-six thousand, five hundred thirteen".