666739937666 has 48 divisors (see below), whose sum is σ = 1141351918560. Its totient is φ = 289677389760.

The previous prime is 666739937641. The next prime is 666739937671.

666739937666 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 666739937593 and 666739937602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16657265 + ... + 16697243.

It is an arithmetic number, because the mean of its divisors is an integer number (23778164970).

Almost surely, 2^666739937666 is an apocalyptic number.

666739937666 is a deficient number, since it is larger than the sum of its proper divisors (474611980894).

666739937666 is a wasteful number, since it uses less digits than its factorization.

666739937666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41471 (or 41448 counting only the distinct ones).

The product of its digits is 1666598976, while the sum is 74.

The spelling of 666739937666 in words is "six hundred sixty-six billion, seven hundred thirty-nine million, nine hundred thirty-seven thousand, six hundred sixty-six".