21893472 has 72 divisors (see below), whose sum is σ = 65552760. Its totient is φ = 6912000.

The previous prime is 21893461. The next prime is 21893477. The reversal of 21893472 is 27439812.

21893472 is a `hidden beast` number, since 2 + 189 + 3 + 472 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21893477) 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, 3472 + ... + 7472.

It is an arithmetic number, because the mean of its divisors is an integer number (910455).

Almost surely, 2^21893472 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 21893472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32776380).

21893472 is an abundant number, since it is smaller than the sum of its proper divisors (43659288).

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

21893472 is a wasteful number, since it uses less digits than its factorization.

21893472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4036 (or 4025 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21893472 is about 4679.0460566231. The cubic root of 21893472 is about 279.7509349805.

The spelling of 21893472 in words is "twenty-one million, eight hundred ninety-three thousand, four hundred seventy-two".