21338790 has 32 divisors (see below), whose sum is σ = 55869696. Its totient is φ = 5172960.

The previous prime is 21338783. The next prime is 21338797. The reversal of 21338790 is 9783312.

It is an interprime number because it is at equal distance from previous prime (21338783) and next prime (21338797).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21338797) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32002 + ... + 32661.

It is an arithmetic number, because the mean of its divisors is an integer number (1745928).

Almost surely, 2^21338790 is an apocalyptic number.

21338790 is an abundant number, since it is smaller than the sum of its proper divisors (34530906).

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

21338790 is a wasteful number, since it uses less digits than its factorization.

21338790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64684.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 21338790 is about 4619.3928172434. The cubic root of 21338790 is about 277.3681542329.

The spelling of 21338790 in words is "twenty-one million, three hundred thirty-eight thousand, seven hundred ninety".