21889904 has 10 divisors (see below), whose sum is σ = 42411720. Its totient is φ = 10944944.

The previous prime is 21889877. The next prime is 21889909. The reversal of 21889904 is 40998812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21889909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 684044 + ... + 684075.

It is an arithmetic number, because the mean of its divisors is an integer number (4241172).

Almost surely, 2^21889904 is an apocalyptic number.

It is an amenable number.

21889904 is a deficient number, since it is larger than the sum of its proper divisors (20521816).

21889904 is a wasteful number, since it uses less digits than its factorization.

21889904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1368127 (or 1368121 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 21889904 is about 4678.6647667898. The cubic root of 21889904 is about 279.7357370627.

The spelling of 21889904 in words is "twenty-one million, eight hundred eighty-nine thousand, nine hundred four".