25121631 has 16 divisors (see below), whose sum is σ = 36427104. Its totient is φ = 15335424.

The previous prime is 25121617. The next prime is 25121633. The reversal of 25121631 is 13612152.

It is not a de Polignac number, because 25121631 - 2¹¹ = 25119583 is a prime.

It is a super-2 number, since 2×25121631² = 1262192688200322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 25121598 and 25121607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25121633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4770 + ... + 8543.

It is an arithmetic number, because the mean of its divisors is an integer number (2276694).

Almost surely, 2^25121631 is an apocalyptic number.

25121631 is a deficient number, since it is larger than the sum of its proper divisors (11305473).

25121631 is a wasteful number, since it uses less digits than its factorization.

25121631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13370.

The product of its digits is 360, while the sum is 21.

The square root of 25121631 is about 5012.1483417792. The cubic root of 25121631 is about 292.8752084604.

Adding to 25121631 its reverse (13612152), we get a palindrome (38733783).

It can be divided in two parts, 25121 and 631, that added together give a palindrome (25752).

The spelling of 25121631 in words is "twenty-five million, one hundred twenty-one thousand, six hundred thirty-one".