21623392 has 48 divisors (see below), whose sum is σ = 49986720. Its totient is φ = 9013248.

The previous prime is 21623389. The next prime is 21623411. The reversal of 21623392 is 29332612.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 21623392.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 6984 + ... + 9592.

It is an arithmetic number, because the mean of its divisors is an integer number (1041390).

Almost surely, 2^21623392 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 21623392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24993360).

21623392 is an abundant number, since it is smaller than the sum of its proper divisors (28363328).

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

21623392 is a wasteful number, since it uses less digits than its factorization.

21623392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2663 (or 2655 counting only the distinct ones).

The product of its digits is 3888, while the sum is 28.

The square root of 21623392 is about 4650.0959129893. The cubic root of 21623392 is about 278.5958271232.

The spelling of 21623392 in words is "twenty-one million, six hundred twenty-three thousand, three hundred ninety-two".