21933648 has 120 divisors (see below), whose sum is σ = 68361696. Its totient is φ = 6508800.

The previous prime is 21933643. The next prime is 21933649. The reversal of 21933648 is 84633912.

21933648 is a `hidden beast` number, since 2 + 1 + 9 + 3 + 3 + 648 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21933641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 96511 + ... + 96737.

Almost surely, 2^21933648 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 21933648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34180848).

21933648 is an abundant number, since it is smaller than the sum of its proper divisors (46428048).

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

21933648 is a wasteful number, since it uses less digits than its factorization.

21933648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313 (or 304 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 21933648 is about 4683.3372716472. The cubic root of 21933648 is about 279.9219510353.

The spelling of 21933648 in words is "twenty-one million, nine hundred thirty-three thousand, six hundred forty-eight".