21328722 has 24 divisors (see below), whose sum is σ = 46311564. Its totient is φ = 7094304.

The previous prime is 21328673. The next prime is 21328729. The reversal of 21328722 is 22782312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19793601 + 1535121 = 4449^2 + 1239^2 .

It is not an unprimeable number, because it can be changed into a prime (21328729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10068 + ... + 12000.

Almost surely, 2^21328722 is an apocalyptic number.

21328722 is an abundant number, since it is smaller than the sum of its proper divisors (24982842).

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

21328722 is a wasteful number, since it uses less digits than its factorization.

21328722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2554 (or 2551 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 21328722 is about 4618.3029350618. The cubic root of 21328722 is about 277.3245250505.

The spelling of 21328722 in words is "twenty-one million, three hundred twenty-eight thousand, seven hundred twenty-two".