18219966 has 8 divisors (see below), whose sum is σ = 36439944. Its totient is φ = 6073320.

The previous prime is 18219959. The next prime is 18219983. The reversal of 18219966 is 66991281.

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

18219966 is an admirable number.

It is a super-2 number, since 2×18219966² = 663934322082312, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1518325 + ... + 1518336.

It is an arithmetic number, because the mean of its divisors is an integer number (4554993).

Almost surely, 2^18219966 is an apocalyptic number.

18219966 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18219966 is a wasteful number, since it uses less digits than its factorization.

18219966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3036666.

The product of its digits is 46656, while the sum is 42.

The square root of 18219966 is about 4268.4852114070. The cubic root of 18219966 is about 263.1373645696.

The spelling of 18219966 in words is "eighteen million, two hundred nineteen thousand, nine hundred sixty-six".