21798672 has 40 divisors (see below), whose sum is σ = 64358976. Its totient is φ = 6228096.

The previous prime is 21798653. The next prime is 21798683. The reversal of 21798672 is 27689712.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32103 + ... + 32774.

Almost surely, 2^21798672 is an apocalyptic number.

It is an amenable number.

21798672 is an abundant number, since it is smaller than the sum of its proper divisors (42560304).

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

21798672 is a wasteful number, since it uses less digits than its factorization.

21798672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64895 (or 64889 counting only the distinct ones).

The product of its digits is 84672, while the sum is 42.

The square root of 21798672 is about 4668.9047966306. The cubic root of 21798672 is about 279.3465715359.

It can be divided in two parts, 217 and 98672, that added together give a palindrome (98889).

The spelling of 21798672 in words is "twenty-one million, seven hundred ninety-eight thousand, six hundred seventy-two".