21944646 has 12 divisors (see below), whose sum is σ = 47546772. Its totient is φ = 7314876.

The previous prime is 21944581. The next prime is 21944651. The reversal of 21944646 is 64644912.

21944646 is a `hidden beast` number, since 2 + 1 + 9 + 4 + 4 + 646 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21944646.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 609556 + ... + 609591.

It is an arithmetic number, because the mean of its divisors is an integer number (3962231).

Almost surely, 2^21944646 is an apocalyptic number.

21944646 is an abundant number, since it is smaller than the sum of its proper divisors (25602126).

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

21944646 is a wasteful number, since it uses less digits than its factorization.

21944646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1219155 (or 1219152 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 21944646 is about 4684.5112872102. The cubic root of 21944646 is about 279.9687295010.

The spelling of 21944646 in words is "twenty-one million, nine hundred forty-four thousand, six hundred forty-six".