21881392 has 20 divisors (see below), whose sum is σ = 45656800. Its totient is φ = 10099008.

The previous prime is 21881383. The next prime is 21881459. The reversal of 21881392 is 29318812.

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 3 ways as a sum of consecutive naturals, for example, 52392 + ... + 52807.

It is an arithmetic number, because the mean of its divisors is an integer number (2282840).

Almost surely, 2^21881392 is an apocalyptic number.

It is an amenable number.

21881392 is an abundant number, since it is smaller than the sum of its proper divisors (23775408).

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

21881392 is a wasteful number, since it uses less digits than its factorization.

21881392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105220 (or 105214 counting only the distinct ones).

The product of its digits is 6912, while the sum is 34.

The square root of 21881392 is about 4677.7550170995. The cubic root of 21881392 is about 279.6994734759.

The spelling of 21881392 in words is "twenty-one million, eight hundred eighty-one thousand, three hundred ninety-two".