21890934 has 48 divisors (see below), whose sum is σ = 54093312. Its totient is φ = 6338304.

The previous prime is 21890927. The next prime is 21890959. The reversal of 21890934 is 43909812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1227 + ... + 6729.

It is an arithmetic number, because the mean of its divisors is an integer number (1126944).

Almost surely, 2^21890934 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21890934, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27046656).

21890934 is an abundant number, since it is smaller than the sum of its proper divisors (32202378).

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

21890934 is a wasteful number, since it uses less digits than its factorization.

21890934 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5541 (or 5538 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 21890934 is about 4678.7748396348. The cubic root of 21890934 is about 279.7401245235.

The spelling of 21890934 in words is "twenty-one million, eight hundred ninety thousand, nine hundred thirty-four".