25687813 has 4 divisors (see below), whose sum is σ = 26285248. Its totient is φ = 25090380.

The previous prime is 25687801. The next prime is 25687817. The reversal of 25687813 is 31878652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25687813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25687817) 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, 298653 + ... + 298738.

It is an arithmetic number, because the mean of its divisors is an integer number (6571312).

Almost surely, 2^25687813 is an apocalyptic number.

It is an amenable number.

25687813 is a deficient number, since it is larger than the sum of its proper divisors (597435).

25687813 is an equidigital number, since it uses as much as digits as its factorization.

25687813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597434.

The product of its digits is 80640, while the sum is 40.

The square root of 25687813 is about 5068.3146113871. The cubic root of 25687813 is about 295.0591205841.

The spelling of 25687813 in words is "twenty-five million, six hundred eighty-seven thousand, eight hundred thirteen".