21851992 has 32 divisors (see below), whose sum is σ = 42379200. Its totient is φ = 10557184.

The previous prime is 21851989. The next prime is 21852011. The reversal of 21851992 is 29915812.

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, 33138 + ... + 33790.

It is an arithmetic number, because the mean of its divisors is an integer number (1324350).

Almost surely, 2^21851992 is an apocalyptic number.

It is an amenable number.

21851992 is a deficient number, since it is larger than the sum of its proper divisors (20527208).

21851992 is a wasteful number, since it uses less digits than its factorization.

21851992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795 (or 791 counting only the distinct ones).

The product of its digits is 12960, while the sum is 37.

The square root of 21851992 is about 4674.6114277018. The cubic root of 21851992 is about 279.5741485701.

The spelling of 21851992 in words is "twenty-one million, eight hundred fifty-one thousand, nine hundred ninety-two".