625696820081 has 2 divisors, whose sum is σ = 625696820082. Its totient is φ = 625696820080.

The previous prime is 625696820071. The next prime is 625696820101. The reversal of 625696820081 is 180028696526.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 424831507681 + 200865312400 = 651791^2 + 448180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-625696820081 is a prime.

It is a super-2 number, since 2×625696820081² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (625696820071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312848410040 + 312848410041.

It is an arithmetic number, because the mean of its divisors is an integer number (312848410041).

Almost surely, 2^625696820081 is an apocalyptic number.

It is an amenable number.

625696820081 is a deficient number, since it is larger than the sum of its proper divisors (1).

625696820081 is an equidigital number, since it uses as much as digits as its factorization.

625696820081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2488320, while the sum is 53.

The spelling of 625696820081 in words is "six hundred twenty-five billion, six hundred ninety-six million, eight hundred twenty thousand, eighty-one".