21913604 has 6 divisors (see below), whose sum is σ = 38348814. Its totient is φ = 10956800.

The previous prime is 21913601. The next prime is 21913627. The reversal of 21913604 is 40631912.

It can be written as a sum of positive squares in only one way, i.e., 19360000 + 2553604 = 4400^2 + 1598^2 .

It is not an unprimeable number, because it can be changed into a prime (21913601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2739197 + ... + 2739204.

It is an arithmetic number, because the mean of its divisors is an integer number (6391469).

Almost surely, 2^21913604 is an apocalyptic number.

It is an amenable number.

21913604 is a deficient number, since it is larger than the sum of its proper divisors (16435210).

21913604 is a wasteful number, since it uses less digits than its factorization.

21913604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5478405 (or 5478403 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21913604 is about 4681.1968555061. The cubic root of 21913604 is about 279.8366564295.

The spelling of 21913604 in words is "twenty-one million, nine hundred thirteen thousand, six hundred four".