668817777240 has 48 divisors (see below), whose sum is σ = 2173657777200. Its totient is φ = 178351407168.

The previous prime is 668817777223. The next prime is 668817777241. The reversal of 668817777240 is 42777718866.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668817777241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 928913220 + ... + 928913939.

It is an arithmetic number, because the mean of its divisors is an integer number (45284537025).

Almost surely, 2^668817777240 is an apocalyptic number.

668817777240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668817777240 is an abundant number, since it is smaller than the sum of its proper divisors (1504839999960).

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

668817777240 is a wasteful number, since it uses less digits than its factorization.

668817777240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1857827176 (or 1857827169 counting only the distinct ones).

The product of its (nonzero) digits is 44255232, while the sum is 63.

The spelling of 668817777240 in words is "six hundred sixty-eight billion, eight hundred seventeen million, seven hundred seventy-seven thousand, two hundred forty".