21013208 has 16 divisors (see below), whose sum is σ = 39464880. Its totient is φ = 10489248.

The previous prime is 21013189. The next prime is 21013217. The reversal of 21013208 is 80231012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4010 + ... + 7622.

It is an arithmetic number, because the mean of its divisors is an integer number (2466555).

Almost surely, 2^21013208 is an apocalyptic number.

It is an amenable number.

21013208 is a deficient number, since it is larger than the sum of its proper divisors (18451672).

21013208 is a wasteful number, since it uses less digits than its factorization.

21013208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4346 (or 4342 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21013208 is about 4584.0165793766. The cubic root of 21013208 is about 275.9502465802.

The spelling of 21013208 in words is "twenty-one million, thirteen thousand, two hundred eight".