666731970 has 24 divisors (see below), whose sum is σ = 1733503356. Its totient is φ = 177795168.

The previous prime is 666731957. The next prime is 666731977. The reversal of 666731970 is 79137666.

It can be written as a sum of positive squares in 2 ways, for example, as 591511041 + 75220929 = 24321^2 + 8673^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (666731977) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3703977 + ... + 3704156.

Almost surely, 2^666731970 is an apocalyptic number.

666731970 is an abundant number, since it is smaller than the sum of its proper divisors (1066771386).

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

666731970 is a wasteful number, since it uses less digits than its factorization.

666731970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7408146 (or 7408143 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 45.

The square root of 666731970 is about 25821.1535373616. The cubic root of 666731970 is about 873.6089876631.

The spelling of 666731970 in words is "six hundred sixty-six million, seven hundred thirty-one thousand, nine hundred seventy".