21954186 has 16 divisors (see below), whose sum is σ = 48787200. Its totient is φ = 7318044.

The previous prime is 21954173. The next prime is 21954187. The reversal of 21954186 is 68145912.

It is a self number, because there is not a number n which added to its sum of digits gives 21954186.

It is not an unprimeable number, because it can be changed into a prime (21954187) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 203226 + ... + 203333.

It is an arithmetic number, because the mean of its divisors is an integer number (3049200).

Almost surely, 2^21954186 is an apocalyptic number.

21954186 is an abundant number, since it is smaller than the sum of its proper divisors (26833014).

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

21954186 is a wasteful number, since it uses less digits than its factorization.

21954186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406570 (or 406564 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 21954186 is about 4685.5294257960. The cubic root of 21954186 is about 280.0092939092.

The spelling of 21954186 in words is "twenty-one million, nine hundred fifty-four thousand, one hundred eighty-six".