665867423880 has 384 divisors, whose sum is σ = 2373932171520. Its totient is φ = 167513702400.

The previous prime is 665867423873. The next prime is 665867423887. The reversal of 665867423880 is 88324768566.

665867423880 is a `hidden beast` number, since 6 + 6 + 586 + 7 + 42 + 3 + 8 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (665867423873) and next prime (665867423887).

It is not an unprimeable number, because it can be changed into a prime (665867423887) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16299480 + ... + 16340280.

It is an arithmetic number, because the mean of its divisors is an integer number (6182115030).

Almost surely, 2^665867423880 is an apocalyptic number.

665867423880 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 665867423880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1186966085760).

665867423880 is an abundant number, since it is smaller than the sum of its proper divisors (1708064747640).

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

665867423880 is a wasteful number, since it uses less digits than its factorization.

665867423880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40923 (or 40907 counting only the distinct ones).

The product of its (nonzero) digits is 92897280, while the sum is 63.

The spelling of 665867423880 in words is "six hundred sixty-five billion, eight hundred sixty-seven million, four hundred twenty-three thousand, eight hundred eighty".