204156666 has 64 divisors (see below), whose sum is σ = 525864960. Its totient is φ = 57501360.

The previous prime is 204156649. The next prime is 204156679. The reversal of 204156666 is 666651402.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 204156666.

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, 23035 + ... + 30641.

It is an arithmetic number, because the mean of its divisors is an integer number (8216640).

Almost surely, 2^204156666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 204156666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262932480).

204156666 is an abundant number, since it is smaller than the sum of its proper divisors (321708294).

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

204156666 is a wasteful number, since it uses less digits than its factorization.

204156666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7696 (or 7690 counting only the distinct ones).

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

The square root of 204156666 is about 14288.3402115151. The cubic root of 204156666 is about 588.8271885490.

The spelling of 204156666 in words is "two hundred four million, one hundred fifty-six thousand, six hundred sixty-six".