666630881280 has 1824 divisors, whose sum is σ = 3077875067904. Its totient is φ = 134536495104.

The previous prime is 666630881263. The next prime is 666630881309. The reversal of 666630881280 is 82188036666.

It is a super-2 number, since 2×666630881280² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 28983951349 + ... + 28983951371.

Almost surely, 2^666630881280 is an apocalyptic number.

666630881280 is a gapful number since it is divisible by the number (60) 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 666630881280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1538937533952).

666630881280 is an abundant number, since it is smaller than the sum of its proper divisors (2411244186624).

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

666630881280 is an frugal number, since it uses more digits than its factorization.

666630881280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

The spelling of 666630881280 in words is "six hundred sixty-six billion, six hundred thirty million, eight hundred eighty-one thousand, two hundred eighty".