21866382 has 32 divisors (see below), whose sum is σ = 48787200. Its totient is φ = 7259544.

The previous prime is 21866333. The next prime is 21866387. The reversal of 21866382 is 28366812.

21866382 is a `hidden beast` number, since 2 + 18 + 6 + 638 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21866387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15919 + ... + 17237.

It is an arithmetic number, because the mean of its divisors is an integer number (1524600).

Almost surely, 2^21866382 is an apocalyptic number.

21866382 is an abundant number, since it is smaller than the sum of its proper divisors (26920818).

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

21866382 is a wasteful number, since it uses less digits than its factorization.

21866382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1637 (or 1631 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21866382 is about 4676.1503397560. The cubic root of 21866382 is about 279.6355036055.

The spelling of 21866382 in words is "twenty-one million, eight hundred sixty-six thousand, three hundred eighty-two".