21788332 has 6 divisors (see below), whose sum is σ = 38129588. Its totient is φ = 10894164.

The previous prime is 21788297. The next prime is 21788341. The reversal of 21788332 is 23388712.

It is a super-2 number, since 2×21788332² = 949462822684448, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2723538 + ... + 2723545.

Almost surely, 2^21788332 is an apocalyptic number.

It is an amenable number.

21788332 is a deficient number, since it is larger than the sum of its proper divisors (16341256).

21788332 is a wasteful number, since it uses less digits than its factorization.

21788332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5447087 (or 5447085 counting only the distinct ones).

The product of its digits is 16128, while the sum is 34.

The square root of 21788332 is about 4667.7973392169. The cubic root of 21788332 is about 279.3023960562.

The spelling of 21788332 in words is "twenty-one million, seven hundred eighty-eight thousand, three hundred thirty-two".