666556402464 has 72 divisors (see below), whose sum is σ = 1919513756160. Its totient is φ = 219372985728.

The previous prime is 666556402451. The next prime is 666556402469. The reversal of 666556402464 is 464204655666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a self number, because there is not a number n which added to its sum of digits gives 666556402464.

It is not an unprimeable number, because it can be changed into a prime (666556402469) 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, 14625552 + ... + 14671055.

It is an arithmetic number, because the mean of its divisors is an integer number (26659913280).

Almost surely, 2^666556402464 is an apocalyptic number.

It is an amenable number.

666556402464 is an abundant number, since it is smaller than the sum of its proper divisors (1252957353696).

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

666556402464 is a wasteful number, since it uses less digits than its factorization.

666556402464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29296702 (or 29296691 counting only the distinct ones).

The product of its (nonzero) digits is 24883200, while the sum is 54.

The spelling of 666556402464 in words is "six hundred sixty-six billion, five hundred fifty-six million, four hundred two thousand, four hundred sixty-four".