21939484 has 12 divisors (see below), whose sum is σ = 43879024. Its totient is φ = 9402624.

The previous prime is 21939481. The next prime is 21939517. The reversal of 21939484 is 48493912.

21939484 is an admirable number.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21939481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 391749 + ... + 391804.

Almost surely, 2^21939484 is an apocalyptic number.

It is an amenable number.

21939484 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21939484 is a wasteful number, since it uses less digits than its factorization.

21939484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 783564 (or 783562 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 21939484 is about 4683.9602901818. The cubic root of 21939484 is about 279.9467755977.

The spelling of 21939484 in words is "twenty-one million, nine hundred thirty-nine thousand, four hundred eighty-four".