21722504 has 8 divisors (see below), whose sum is σ = 40729710. Its totient is φ = 10861248.

The previous prime is 21722489. The next prime is 21722509. The reversal of 21722504 is 40522712.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 11546404 + 10176100 = 3398^2 + 3190^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21722504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1357649 + ... + 1357664.

Almost surely, 2^21722504 is an apocalyptic number.

It is an amenable number.

21722504 is a deficient number, since it is larger than the sum of its proper divisors (19007206).

21722504 is a wasteful number, since it uses less digits than its factorization.

21722504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2715319 (or 2715315 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21722504 is about 4660.7407136634. The cubic root of 21722504 is about 279.0208315103.

The spelling of 21722504 in words is "twenty-one million, seven hundred twenty-two thousand, five hundred four".