21719304 has 24 divisors (see below), whose sum is σ = 58823310. Its totient is φ = 7239744.

The previous prime is 21719303. The next prime is 21719309. The reversal of 21719304 is 40391712.

It can be written as a sum of positive squares in only one way, i.e., 11492100 + 10227204 = 3390^2 + 3198^2 .

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 (21719303) 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, 150757 + ... + 150900.

Almost surely, 2^21719304 is an apocalyptic number.

21719304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21719304 is an abundant number, since it is smaller than the sum of its proper divisors (37104006).

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

21719304 is a wasteful number, since it uses less digits than its factorization.

21719304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301669 (or 301662 counting only the distinct ones).

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

The square root of 21719304 is about 4660.3974079471. The cubic root of 21719304 is about 279.0071297365.

The spelling of 21719304 in words is "twenty-one million, seven hundred nineteen thousand, three hundred four".