666868620040 has 64 divisors (see below), whose sum is σ = 1717353509760. Its totient is φ = 228300871680.

The previous prime is 666868619987. The next prime is 666868620049. The reversal of 666868620040 is 40026868666.

It is a self number, because there is not a number n which added to its sum of digits gives 666868620040.

It is not an unprimeable number, because it can be changed into a prime (666868620049) 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 15 ways as a sum of consecutive naturals, for example, 1581006 + ... + 1957885.

It is an arithmetic number, because the mean of its divisors is an integer number (26833648590).

Almost surely, 2^666868620040 is an apocalyptic number.

It is an amenable number.

666868620040 is an abundant number, since it is smaller than the sum of its proper divisors (1050484889720).

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

666868620040 is a wasteful number, since it uses less digits than its factorization.

666868620040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3539582 (or 3539578 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 52.

The spelling of 666868620040 in words is "six hundred sixty-six billion, eight hundred sixty-eight million, six hundred twenty thousand, forty".