21379624 has 32 divisors (see below), whose sum is σ = 46005120. Its totient is φ = 9124416.

The previous prime is 21379619. The next prime is 21379663. The reversal of 21379624 is 42697312.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21379624.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15757 + ... + 17059.

It is an arithmetic number, because the mean of its divisors is an integer number (1437660).

Almost surely, 2^21379624 is an apocalyptic number.

It is an amenable number.

21379624 is an abundant number, since it is smaller than the sum of its proper divisors (24625496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21379624 is a wasteful number, since it uses less digits than its factorization.

21379624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1609 (or 1605 counting only the distinct ones).

The product of its digits is 18144, while the sum is 34.

The square root of 21379624 is about 4623.8105497522. The cubic root of 21379624 is about 277.5449657946.

The spelling of 21379624 in words is "twenty-one million, three hundred seventy-nine thousand, six hundred twenty-four".