21868492 has 12 divisors (see below), whose sum is σ = 39933936. Its totient is φ = 10458800.

The previous prime is 21868471. The next prime is 21868493. The reversal of 21868492 is 29486812.

It is not an unprimeable number, because it can be changed into a prime (21868493) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118759 + ... + 118942.

It is an arithmetic number, because the mean of its divisors is an integer number (3327828).

Almost surely, 2^21868492 is an apocalyptic number.

It is an amenable number.

21868492 is a deficient number, since it is larger than the sum of its proper divisors (18065444).

21868492 is a wasteful number, since it uses less digits than its factorization.

21868492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237728 (or 237726 counting only the distinct ones).

The product of its digits is 55296, while the sum is 40.

The square root of 21868492 is about 4676.3759472480. The cubic root of 21868492 is about 279.6444978070.

The spelling of 21868492 in words is "twenty-one million, eight hundred sixty-eight thousand, four hundred ninety-two".