21913704 has 24 divisors (see below), whose sum is σ = 59349810. Its totient is φ = 7304544.

The previous prime is 21913691. The next prime is 21913709. The reversal of 21913704 is 40731912.

It can be written as a sum of positive squares in only one way, i.e., 14062500 + 7851204 = 3750^2 + 2802^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21913709) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 152107 + ... + 152250.

Almost surely, 2^21913704 is an apocalyptic number.

21913704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21913704 is an abundant number, since it is smaller than the sum of its proper divisors (37436106).

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

21913704 is a wasteful number, since it uses less digits than its factorization.

21913704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304369 (or 304362 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21913704 is about 4681.2075365230. The cubic root of 21913704 is about 279.8370820954.

The spelling of 21913704 in words is "twenty-one million, nine hundred thirteen thousand, seven hundred four".