25662629561 has 2 divisors, whose sum is σ = 25662629562. Its totient is φ = 25662629560.

The previous prime is 25662629543. The next prime is 25662629639. The reversal of 25662629561 is 16592626652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22654765225 + 3007864336 = 150515^2 + 54844^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25662629561 is a prime.

It is a super-2 number, since 2×25662629561² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25662629501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12831314780 + 12831314781.

It is an arithmetic number, because the mean of its divisors is an integer number (12831314781).

Almost surely, 2^25662629561 is an apocalyptic number.

It is an amenable number.

25662629561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25662629561 is an equidigital number, since it uses as much as digits as its factorization.

25662629561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2332800, while the sum is 50.

The spelling of 25662629561 in words is "twenty-five billion, six hundred sixty-two million, six hundred twenty-nine thousand, five hundred sixty-one".