51720272641 has 2 divisors, whose sum is σ = 51720272642. Its totient is φ = 51720272640.

The previous prime is 51720272587. The next prime is 51720272657. The reversal of 51720272641 is 14627202715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49773610000 + 1946662641 = 223100^2 + 44121^2 .

It is a cyclic number.

It is not a de Polignac number, because 51720272641 - 2²⁷ = 51586054913 is a prime.

It is a super-2 number, since 2×51720272641² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51720272641.

It is not a weakly prime, because it can be changed into another prime (51720272671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860136320 + 25860136321.

It is an arithmetic number, because the mean of its divisors is an integer number (25860136321).

Almost surely, 2^51720272641 is an apocalyptic number.

It is an amenable number.

51720272641 is a deficient number, since it is larger than the sum of its proper divisors (1).

51720272641 is an equidigital number, since it uses as much as digits as its factorization.

51720272641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 47040, while the sum is 37.

The spelling of 51720272641 in words is "fifty-one billion, seven hundred twenty million, two hundred seventy-two thousand, six hundred forty-one".