204221664 has 72 divisors (see below), whose sum is σ = 585296712. Its totient is φ = 67541760.

The previous prime is 204221657. The next prime is 204221687. The reversal of 204221664 is 466122402.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35022 + ... + 40434.

It is an arithmetic number, because the mean of its divisors is an integer number (8129121).

Almost surely, 2^204221664 is an apocalyptic number.

204221664 is a gapful number since it is divisible by the number (24) 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 204221664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292648356).

204221664 is an abundant number, since it is smaller than the sum of its proper divisors (381075048).

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

204221664 is a wasteful number, since it uses less digits than its factorization.

204221664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5560 (or 5549 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 204221664 is about 14290.6145424191. The cubic root of 204221664 is about 588.8896708400.

The spelling of 204221664 in words is "two hundred four million, two hundred twenty-one thousand, six hundred sixty-four".