666123264 has 132 divisors (see below), whose sum is σ = 1995399224. Its totient is φ = 221958144.

The previous prime is 666123253. The next prime is 666123281. The reversal of 666123264 is 462321666.

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

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 247494 + ... + 250170.

Almost surely, 2^666123264 is an apocalyptic number.

666123264 is a gapful number since it is divisible by the number (64) 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 666123264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997699612).

666123264 is an abundant number, since it is smaller than the sum of its proper divisors (1329275960).

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

666123264 is an equidigital number, since it uses as much as digits as its factorization.

666123264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2712 (or 2682 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 666123264 is about 25809.3638821262. The cubic root of 666123264 is about 873.3430472409.

The spelling of 666123264 in words is "six hundred sixty-six million, one hundred twenty-three thousand, two hundred sixty-four".