21938492 has 6 divisors (see below), whose sum is σ = 38392368. Its totient is φ = 10969244.

The previous prime is 21938491. The next prime is 21938533. The reversal of 21938492 is 29483912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21938491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2742308 + ... + 2742315.

It is an arithmetic number, because the mean of its divisors is an integer number (6398728).

Almost surely, 2^21938492 is an apocalyptic number.

It is an amenable number.

21938492 is a deficient number, since it is larger than the sum of its proper divisors (16453876).

21938492 is a wasteful number, since it uses less digits than its factorization.

21938492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5484627 (or 5484625 counting only the distinct ones).

The product of its digits is 31104, while the sum is 38.

The square root of 21938492 is about 4683.8543956874. The cubic root of 21938492 is about 279.9425562431.

The spelling of 21938492 in words is "twenty-one million, nine hundred thirty-eight thousand, four hundred ninety-two".