21273388 has 12 divisors (see below), whose sum is σ = 39187960. Its totient is φ = 10076832.

The previous prime is 21273359. The next prime is 21273391. The reversal of 21273388 is 88337212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139881 + ... + 140032.

Almost surely, 2^21273388 is an apocalyptic number.

It is an amenable number.

21273388 is a deficient number, since it is larger than the sum of its proper divisors (17914572).

21273388 is a wasteful number, since it uses less digits than its factorization.

21273388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279936 (or 279934 counting only the distinct ones).

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

The square root of 21273388 is about 4612.3083158002. The cubic root of 21273388 is about 277.0844924644.

The spelling of 21273388 in words is "twenty-one million, two hundred seventy-three thousand, three hundred eighty-eight".