216666900 has 180 divisors, whose sum is σ = 733515552. Its totient is φ = 55218240.

The previous prime is 216666893. The next prime is 216666941. The reversal of 216666900 is 9666612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×216666900² = 93889091111220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 185719 + ... + 186881.

Almost surely, 2^216666900 is an apocalyptic number.

216666900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216666900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (366757776).

216666900 is an abundant number, since it is smaller than the sum of its proper divisors (516848652).

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

216666900 is a wasteful number, since it uses less digits than its factorization.

216666900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1212 (or 1196 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 216666900 is about 14719.6093698168. The cubic root of 216666900 is about 600.6168655774.

The spelling of 216666900 in words is "two hundred sixteen million, six hundred sixty-six thousand, nine hundred".