25505631 has 32 divisors (see below), whose sum is σ = 39168000. Its totient is φ = 16394400.

The previous prime is 25505629. The next prime is 25505633. The reversal of 25505631 is 13650552.

25505631 is a `hidden beast` number, since 25 + 5 + 0 + 5 + 631 = 666.

It is an interprime number because it is at equal distance from previous prime (25505629) and next prime (25505633).

It is not a de Polignac number, because 25505631 - 2¹ = 25505629 is a prime.

It is a super-2 number, since 2×25505631² = 1301074425416322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 25505595 and 25505604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25505633) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 128070 + ... + 128268.

It is an arithmetic number, because the mean of its divisors is an integer number (1224000).

Almost surely, 2^25505631 is an apocalyptic number.

25505631 is a deficient number, since it is larger than the sum of its proper divisors (13662369).

25505631 is a wasteful number, since it uses less digits than its factorization.

25505631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356 (or 350 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 25505631 is about 5050.3099904857. The cubic root of 25505631 is about 294.3599298545.

The spelling of 25505631 in words is "twenty-five million, five hundred five thousand, six hundred thirty-one".