21372672 has 72 divisors (see below), whose sum is σ = 60265296. Its totient is φ = 6701056.

The previous prime is 21372653. The next prime is 21372679. The reversal of 21372672 is 27627312.

It is a super-2 number, since 2×21372672² = 913582216839168, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21372679) 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, 12238 + ... + 13874.

It is an arithmetic number, because the mean of its divisors is an integer number (837018).

Almost surely, 2^21372672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21372672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30132648).

21372672 is an abundant number, since it is smaller than the sum of its proper divisors (38892624).

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

21372672 is a wasteful number, since it uses less digits than its factorization.

21372672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673 (or 1659 counting only the distinct ones).

The product of its digits is 7056, while the sum is 30.

The square root of 21372672 is about 4623.0587277256. The cubic root of 21372672 is about 277.5148794878.

Adding to 21372672 its reverse (27627312), we get a palindrome (48999984).

The spelling of 21372672 in words is "twenty-one million, three hundred seventy-two thousand, six hundred seventy-two".