21816832 has 20 divisors (see below), whose sum is σ = 43592076. Its totient is φ = 10908160.

The previous prime is 21816803. The next prime is 21816841. The reversal of 21816832 is 23861812.

It is a junction number, because it is equal to n+sod(n) for n = 21816794 and 21816803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20794 + ... + 21817.

Almost surely, 2^21816832 is an apocalyptic number.

It is an amenable number.

21816832 is a deficient number, since it is larger than the sum of its proper divisors (21775244).

21816832 is an frugal number, since it uses more digits than its factorization.

21816832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42629 (or 42613 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 21816832 is about 4670.8491733303. The cubic root of 21816832 is about 279.4241225242.

The spelling of 21816832 in words is "twenty-one million, eight hundred sixteen thousand, eight hundred thirty-two".