21938922 has 12 divisors (see below), whose sum is σ = 47534370. Its totient is φ = 7312968.

The previous prime is 21938899. The next prime is 21938923. The reversal of 21938922 is 22983912.

It can be written as a sum of positive squares in only one way, i.e., 13242321 + 8696601 = 3639^2 + 2949^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21938923) by changing a digit.

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, 609397 + ... + 609432.

Almost surely, 2^21938922 is an apocalyptic number.

21938922 is an abundant number, since it is smaller than the sum of its proper divisors (25595448).

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

21938922 is a wasteful number, since it uses less digits than its factorization.

21938922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1218837 (or 1218834 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 21938922 is about 4683.9002978287. The cubic root of 21938922 is about 279.9443852128.

The spelling of 21938922 in words is "twenty-one million, nine hundred thirty-eight thousand, nine hundred twenty-two".