21905948 has 24 divisors (see below), whose sum is σ = 39547200. Its totient is φ = 10611648.

The previous prime is 21905929. The next prime is 21905953. The reversal of 21905948 is 84950912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19958 + ... + 21026.

It is an arithmetic number, because the mean of its divisors is an integer number (1647800).

Almost surely, 2^21905948 is an apocalyptic number.

It is an amenable number.

21905948 is a deficient number, since it is larger than the sum of its proper divisors (17641252).

21905948 is a wasteful number, since it uses less digits than its factorization.

21905948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229 (or 1227 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 21905948 is about 4680.3790444792. The cubic root of 21905948 is about 279.8040636013.

The spelling of 21905948 in words is "twenty-one million, nine hundred five thousand, nine hundred forty-eight".