666702207665 has 16 divisors (see below), whose sum is σ = 861752219328. Its totient is φ = 492238036416.

The previous prime is 666702207641. The next prime is 666702207679. The reversal of 666702207665 is 566702207666.

666702207665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666702207665 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 661847 + ... + 1330956.

It is an arithmetic number, because the mean of its divisors is an integer number (53859513708).

Almost surely, 2^666702207665 is an apocalyptic number.

666702207665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

666702207665 is a deficient number, since it is larger than the sum of its proper divisors (195050011663).

666702207665 is a wasteful number, since it uses less digits than its factorization.

666702207665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1997968.

The product of its (nonzero) digits is 7620480, while the sum is 53.

Subtracting from 666702207665 its reverse (566702207666), we obtain a palindrome (99999999999).

The spelling of 666702207665 in words is "six hundred sixty-six billion, seven hundred two million, two hundred seven thousand, six hundred sixty-five".