21789572 has 24 divisors (see below), whose sum is σ = 44404416. Its totient is φ = 9161568.

The previous prime is 21789571. The next prime is 21789577. The reversal of 21789572 is 27598712.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21789571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5858 + ... + 8825.

It is an arithmetic number, because the mean of its divisors is an integer number (1850184).

Almost surely, 2^21789572 is an apocalyptic number.

It is an amenable number.

21789572 is an abundant number, since it is smaller than the sum of its proper divisors (22614844).

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

21789572 is a wasteful number, since it uses less digits than its factorization.

21789572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14747 (or 14745 counting only the distinct ones).

The product of its digits is 70560, while the sum is 41.

The square root of 21789572 is about 4667.9301622882. The cubic root of 21789572 is about 279.3076944334.

The spelling of 21789572 in words is "twenty-one million, seven hundred eighty-nine thousand, five hundred seventy-two".