25644131081 has 2 divisors, whose sum is σ = 25644131082. Its totient is φ = 25644131080.

The previous prime is 25644131041. The next prime is 25644131087. The reversal of 25644131081 is 18013144652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20683041856 + 4961089225 = 143816^2 + 70435^2 .

It is a cyclic number.

It is not a de Polignac number, because 25644131081 - 2³⁰ = 24570389257 is a prime.

It is a super-2 number, since 2×25644131081² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25644131087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12822065540 + 12822065541.

It is an arithmetic number, because the mean of its divisors is an integer number (12822065541).

Almost surely, 2^25644131081 is an apocalyptic number.

It is an amenable number.

25644131081 is a deficient number, since it is larger than the sum of its proper divisors (1).

25644131081 is an equidigital number, since it uses as much as digits as its factorization.

25644131081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 35.

The spelling of 25644131081 in words is "twenty-five billion, six hundred forty-four million, one hundred thirty-one thousand, eighty-one".