21995825 has 12 divisors (see below), whose sum is σ = 28710960. Its totient is φ = 16670160.

The previous prime is 21995801. The next prime is 21995839. The reversal of 21995825 is 52859912.

It is not a de Polignac number, because 21995825 - 2¹⁸ = 21733681 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22679 + ... + 23628.

It is an arithmetic number, because the mean of its divisors is an integer number (2392580).

Almost surely, 2^21995825 is an apocalyptic number.

21995825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21995825 is a deficient number, since it is larger than the sum of its proper divisors (6715135).

21995825 is a wasteful number, since it uses less digits than its factorization.

21995825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46336 (or 46331 counting only the distinct ones).

The product of its digits is 64800, while the sum is 41.

The square root of 21995825 is about 4689.9706822111. The cubic root of 21995825 is about 280.1862069227.

The spelling of 21995825 in words is "twenty-one million, nine hundred ninety-five thousand, eight hundred twenty-five".