51656758446521 has 2 divisors, whose sum is σ = 51656758446522. Its totient is φ = 51656758446520.

The previous prime is 51656758446497. The next prime is 51656758446529. The reversal of 51656758446521 is 12564485765615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35175147786496 + 16481610660025 = 5930864^2 + 4059755^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51656758446521 is a prime.

It is not a weakly prime, because it can be changed into another prime (51656758446529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25828379223260 + 25828379223261.

It is an arithmetic number, because the mean of its divisors is an integer number (25828379223261).

Almost surely, 2^{51656758446521} is an apocalyptic number.

It is an amenable number.

51656758446521 is a deficient number, since it is larger than the sum of its proper divisors (1).

51656758446521 is an equidigital number, since it uses as much as digits as its factorization.

51656758446521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920000, while the sum is 65.

The spelling of 51656758446521 in words is "fifty-one trillion, six hundred fifty-six billion, seven hundred fifty-eight million, four hundred forty-six thousand, five hundred twenty-one".