25972821 has 24 divisors (see below), whose sum is σ = 45399744. Its totient is φ = 13968000.

The previous prime is 25972813. The next prime is 25972831. The reversal of 25972821 is 12827952.

It is not a de Polignac number, because 25972821 - 2³ = 25972813 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25972831) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11055 + ... + 13196.

It is an arithmetic number, because the mean of its divisors is an integer number (1891656).

Almost surely, 2^25972821 is an apocalyptic number.

25972821 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25972821 is a deficient number, since it is larger than the sum of its proper divisors (19426923).

25972821 is a wasteful number, since it uses less digits than its factorization.

25972821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24281 (or 24278 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 25972821 is about 5096.3536965168. The cubic root of 25972821 is about 296.1463430545.

The spelling of 25972821 in words is "twenty-five million, nine hundred seventy-two thousand, eight hundred twenty-one".