216664650 has 72 divisors (see below), whose sum is σ = 583917984. Its totient is φ = 57597600.

The previous prime is 216664649. The next prime is 216664661. The reversal of 216664650 is 56466612.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 209635 + ... + 210665.

It is an arithmetic number, because the mean of its divisors is an integer number (8109972).

Almost surely, 2^216664650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216664650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (291958992).

216664650 is an abundant number, since it is smaller than the sum of its proper divisors (367253334).

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

216664650 is a wasteful number, since it uses less digits than its factorization.

216664650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1516 (or 1508 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 216664650 is about 14719.5329409598. The cubic root of 216664650 is about 600.6147865141.

The spelling of 216664650 in words is "two hundred sixteen million, six hundred sixty-four thousand, six hundred fifty".