21385628 has 12 divisors (see below), whose sum is σ = 40827192. Its totient is φ = 9720720.

The previous prime is 21385627. The next prime is 21385633. The reversal of 21385628 is 82658312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385627) by changing a digit.

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, 242975 + ... + 243062.

It is an arithmetic number, because the mean of its divisors is an integer number (3402266).

Almost surely, 2^21385628 is an apocalyptic number.

It is an amenable number.

21385628 is a deficient number, since it is larger than the sum of its proper divisors (19441564).

21385628 is a wasteful number, since it uses less digits than its factorization.

21385628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486052 (or 486050 counting only the distinct ones).

The product of its digits is 23040, while the sum is 35.

The square root of 21385628 is about 4624.4597522305. The cubic root of 21385628 is about 277.5709441749.

The spelling of 21385628 in words is "twenty-one million, three hundred eighty-five thousand, six hundred twenty-eight".