25557018631 has 2 divisors, whose sum is σ = 25557018632. Its totient is φ = 25557018630.

The previous prime is 25557018593. The next prime is 25557018661. The reversal of 25557018631 is 13681075552.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25557018631 - 2¹⁵ = 25556985863 is a prime.

It is a super-2 number, since 2×25557018631² (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 (25557018661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12778509315 + 12778509316.

It is an arithmetic number, because the mean of its divisors is an integer number (12778509316).

Almost surely, 2^25557018631 is an apocalyptic number.

25557018631 is a deficient number, since it is larger than the sum of its proper divisors (1).

25557018631 is an equidigital number, since it uses as much as digits as its factorization.

25557018631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252000, while the sum is 43.

The spelling of 25557018631 in words is "twenty-five billion, five hundred fifty-seven million, eighteen thousand, six hundred thirty-one".