21389612 has 6 divisors (see below), whose sum is σ = 37431828. Its totient is φ = 10694804.

The previous prime is 21389593. The next prime is 21389629. The reversal of 21389612 is 21698312.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2673698 + ... + 2673705.

It is an arithmetic number, because the mean of its divisors is an integer number (6238638).

Almost surely, 2^21389612 is an apocalyptic number.

It is an amenable number.

21389612 is a deficient number, since it is larger than the sum of its proper divisors (16042216).

21389612 is a wasteful number, since it uses less digits than its factorization.

21389612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5347407 (or 5347405 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 21389612 is about 4624.8904851899. The cubic root of 21389612 is about 277.5881796438.

The spelling of 21389612 in words is "twenty-one million, three hundred eighty-nine thousand, six hundred twelve".