21938004 has 36 divisors (see below), whose sum is σ = 60496800. Its totient is φ = 6647760.

The previous prime is 21937991. The next prime is 21938009. The reversal of 21938004 is 40083912.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21938009) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27304 + ... + 28095.

Almost surely, 2^21938004 is an apocalyptic number.

It is an amenable number.

21938004 is an abundant number, since it is smaller than the sum of its proper divisors (38558796).

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

21938004 is a wasteful number, since it uses less digits than its factorization.

21938004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55420 (or 55415 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21938004 is about 4683.8023015495. The cubic root of 21938004 is about 279.9404805462.

The spelling of 21938004 in words is "twenty-one million, nine hundred thirty-eight thousand, four".