25131531 has 4 divisors (see below), whose sum is σ = 33508712. Its totient is φ = 16754352.

The previous prime is 25131529. The next prime is 25131541. The reversal of 25131531 is 13513152.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 25131531 - 2¹ = 25131529 is a prime.

It is a super-2 number, since 2×25131531² = 1263187700807922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25131498 and 25131507.

It is not an unprimeable number, because it can be changed into a prime (25131521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4188586 + ... + 4188591.

It is an arithmetic number, because the mean of its divisors is an integer number (8377178).

Almost surely, 2^25131531 is an apocalyptic number.

25131531 is a deficient number, since it is larger than the sum of its proper divisors (8377181).

25131531 is an equidigital number, since it uses as much as digits as its factorization.

25131531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8377180.

The product of its digits is 450, while the sum is 21.

The square root of 25131531 is about 5013.1358449577. The cubic root of 25131531 is about 292.9136757580.

Adding to 25131531 its reverse (13513152), we get a palindrome (38644683).

The spelling of 25131531 in words is "twenty-five million, one hundred thirty-one thousand, five hundred thirty-one".