666381312 has 66 divisors (see below), whose sum is σ = 1924188188. Its totient is φ = 222124032.

The previous prime is 666381299. The next prime is 666381337. The reversal of 666381312 is 213183666.

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.

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 5 ways as a sum of consecutive naturals, for example, 26938 + ... + 45369.

Almost surely, 2^666381312 is an apocalyptic number.

It is an amenable number.

666381312 is an abundant number, since it is smaller than the sum of its proper divisors (1257806876).

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

666381312 is a wasteful number, since it uses less digits than its factorization.

666381312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72333 (or 72312 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 666381312 is about 25814.3625139185. The cubic root of 666381312 is about 873.4558068176.

It can be divided in two parts, 66 and 6381312, that added together give a triangular number (6381378 = T₃₅₇₂).

The spelling of 666381312 in words is "six hundred sixty-six million, three hundred eighty-one thousand, three hundred twelve".