21798572 has 24 divisors (see below), whose sum is σ = 39986016. Its totient is φ = 10378368.

The previous prime is 21798571. The next prime is 21798599. The reversal of 21798572 is 27589712.

It is not an unprimeable number, because it can be changed into a prime (21798571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28418 + ... + 29174.

It is an arithmetic number, because the mean of its divisors is an integer number (1666084).

Almost surely, 2^21798572 is an apocalyptic number.

It is an amenable number.

21798572 is a deficient number, since it is larger than the sum of its proper divisors (18187444).

21798572 is a wasteful number, since it uses less digits than its factorization.

21798572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097 (or 1095 counting only the distinct ones).

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

The square root of 21798572 is about 4668.8940874687. The cubic root of 21798572 is about 279.3461443738.

It can be divided in two parts, 217 and 98572, that added together give a palindrome (98789).

The spelling of 21798572 in words is "twenty-one million, seven hundred ninety-eight thousand, five hundred seventy-two".