25197590581 has 2 divisors, whose sum is σ = 25197590582. Its totient is φ = 25197590580.

The previous prime is 25197590549. The next prime is 25197590629. The reversal of 25197590581 is 18509579152.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22240949956 + 2956640625 = 149134^2 + 54375^2 .

It is a cyclic number.

It is not a de Polignac number, because 25197590581 - 2⁵ = 25197590549 is a prime.

It is a super-2 number, since 2×25197590581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25197590521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12598795290 + 12598795291.

It is an arithmetic number, because the mean of its divisors is an integer number (12598795291).

Almost surely, 2^25197590581 is an apocalyptic number.

It is an amenable number.

25197590581 is a deficient number, since it is larger than the sum of its proper divisors (1).

25197590581 is an equidigital number, since it uses as much as digits as its factorization.

25197590581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134000, while the sum is 52.

The spelling of 25197590581 in words is "twenty-five billion, one hundred ninety-seven million, five hundred ninety thousand, five hundred eighty-one".