666804264 has 64 divisors (see below), whose sum is σ = 1913241600. Its totient is φ = 189706944.

The previous prime is 666804263. The next prime is 666804331. The reversal of 666804264 is 462408666.

666804264 = 256² + 257² + ... + 1263².

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (666804263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31849 + ... + 48455.

It is an arithmetic number, because the mean of its divisors is an integer number (29894400).

Almost surely, 2^666804264 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666804264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (956620800).

666804264 is an abundant number, since it is smaller than the sum of its proper divisors (1246437336).

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

666804264 is a wasteful number, since it uses less digits than its factorization.

666804264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16862 (or 16858 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 42.

The square root of 666804264 is about 25822.5533981440. The cubic root of 666804264 is about 873.6405617731.

The spelling of 666804264 in words is "six hundred sixty-six million, eight hundred four thousand, two hundred sixty-four".