25521631 has 2 divisors, whose sum is σ = 25521632. Its totient is φ = 25521630.

The previous prime is 25521619. The next prime is 25521637. The reversal of 25521631 is 13612552.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25521631 - 2¹⁵ = 25488863 is a prime.

It is a super-2 number, since 2×25521631² = 1302707297800322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25521596 and 25521605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25521637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12760815 + 12760816.

It is an arithmetic number, because the mean of its divisors is an integer number (12760816).

Almost surely, 2^25521631 is an apocalyptic number.

25521631 is a deficient number, since it is larger than the sum of its proper divisors (1).

25521631 is an equidigital number, since it uses as much as digits as its factorization.

25521631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1800, while the sum is 25.

The square root of 25521631 is about 5051.8938033177. The cubic root of 25521631 is about 294.4214688717.

The spelling of 25521631 in words is "twenty-five million, five hundred twenty-one thousand, six hundred thirty-one".