666504601604406 has 64 divisors (see below), whose sum is σ = 1551220935690240. Its totient is φ = 211724548453440.

The previous prime is 666504601604399. The next prime is 666504601604419. The reversal of 666504601604406 is 604406106405666.

It is a super-2 number, since 2×666504601604406² (a number of 30 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 989770735 + ... + 990443898.

It is an arithmetic number, because the mean of its divisors is an integer number (24237827120160).

Almost surely, 2^{666504601604406} is an apocalyptic number.

666504601604406 is an abundant number, since it is smaller than the sum of its proper divisors (884716334085834).

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

666504601604406 is a wasteful number, since it uses less digits than its factorization.

666504601604406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1980214938 (or 1980214932 counting only the distinct ones).

The product of its (nonzero) digits is 14929920, while the sum is 54.

The spelling of 666504601604406 in words is "six hundred sixty-six trillion, five hundred four billion, six hundred one million, six hundred four thousand, four hundred six".