25551815231 has 2 divisors, whose sum is σ = 25551815232. Its totient is φ = 25551815230.

The previous prime is 25551815227. The next prime is 25551815249. The reversal of 25551815231 is 13251815552.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25551815231 - 2² = 25551815227 is a prime.

It is a super-2 number, since 2×25551815231² (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 (25551815831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12775907615 + 12775907616.

It is an arithmetic number, because the mean of its divisors is an integer number (12775907616).

Almost surely, 2^25551815231 is an apocalyptic number.

25551815231 is a deficient number, since it is larger than the sum of its proper divisors (1).

25551815231 is an equidigital number, since it uses as much as digits as its factorization.

25551815231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60000, while the sum is 38.

The spelling of 25551815231 in words is "twenty-five billion, five hundred fifty-one million, eight hundred fifteen thousand, two hundred thirty-one".