18216690 has 64 divisors (see below), whose sum is σ = 48335616. Its totient is φ = 4370432.

The previous prime is 18216661. The next prime is 18216701. The reversal of 18216690 is 9661281.

It is a super-2 number, since 2×18216690² = 663695589112200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10954 + ... + 12506.

It is an arithmetic number, because the mean of its divisors is an integer number (755244).

Almost surely, 2^18216690 is an apocalyptic number.

18216690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18216690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24167808).

18216690 is an abundant number, since it is smaller than the sum of its proper divisors (30118926).

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

18216690 is a wasteful number, since it uses less digits than its factorization.

18216690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 18216690 is about 4268.1014514653. The cubic root of 18216690 is about 263.1215926837.

The spelling of 18216690 in words is "eighteen million, two hundred sixteen thousand, six hundred ninety".