21722884 has 6 divisors (see below), whose sum is σ = 38015054. Its totient is φ = 10861440.

The previous prime is 21722873. The next prime is 21722887. The reversal of 21722884 is 48822712.

It can be written as a sum of positive squares in only one way, i.e., 21362884 + 360000 = 4622^2 + 600^2 .

It is not an unprimeable number, because it can be changed into a prime (21722887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2715357 + ... + 2715364.

Almost surely, 2^21722884 is an apocalyptic number.

It is an amenable number.

21722884 is a deficient number, since it is larger than the sum of its proper divisors (16292170).

21722884 is a wasteful number, since it uses less digits than its factorization.

21722884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5430725 (or 5430723 counting only the distinct ones).

The product of its digits is 14336, while the sum is 34.

The square root of 21722884 is about 4660.7814795375. The cubic root of 21722884 is about 279.0224585065.

The spelling of 21722884 in words is "twenty-one million, seven hundred twenty-two thousand, eight hundred eighty-four".