21936404 has 48 divisors (see below), whose sum is σ = 45588480. Its totient is φ = 9041760.

The previous prime is 21936389. The next prime is 21936413. The reversal of 21936404 is 40463912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103859 + ... + 104069.

It is an arithmetic number, because the mean of its divisors is an integer number (949760).

Almost surely, 2^21936404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21936404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22794240).

21936404 is an abundant number, since it is smaller than the sum of its proper divisors (23652076).

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

21936404 is a wasteful number, since it uses less digits than its factorization.

21936404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348 (or 346 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 21936404 is about 4683.6314970330. The cubic root of 21936404 is about 279.9336747666.

The spelling of 21936404 in words is "twenty-one million, nine hundred thirty-six thousand, four hundred four".