21938186 has 8 divisors (see below), whose sum is σ = 33125664. Its totient is φ = 10896300.

The previous prime is 21938183. The next prime is 21938197. The reversal of 21938186 is 68183912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21938183) 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, 36020 + ... + 36623.

It is an arithmetic number, because the mean of its divisors is an integer number (4140708).

Almost surely, 2^21938186 is an apocalyptic number.

21938186 is a deficient number, since it is larger than the sum of its proper divisors (11187478).

21938186 is a wasteful number, since it uses less digits than its factorization.

21938186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72796.

The product of its digits is 20736, while the sum is 38.

The square root of 21938186 is about 4683.8217301686. The cubic root of 21938186 is about 279.9412546826.

The spelling of 21938186 in words is "twenty-one million, nine hundred thirty-eight thousand, one hundred eighty-six".