666807911 has 16 divisors (see below), whose sum is σ = 845441280. Its totient is φ = 510780480.

The previous prime is 666807899. The next prime is 666807917. The reversal of 666807911 is 119708666.

It is a de Polignac number, because none of the positive numbers 2^k-666807911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666807917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68846 + ... + 77931.

It is an arithmetic number, because the mean of its divisors is an integer number (52840080).

Almost surely, 2^666807911 is an apocalyptic number.

666807911 is a deficient number, since it is larger than the sum of its proper divisors (178633369).

666807911 is a wasteful number, since it uses less digits than its factorization.

666807911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146854.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 666807911 is about 25822.6240146117. The cubic root of 666807911 is about 873.6421545250.

The spelling of 666807911 in words is "six hundred sixty-six million, eight hundred seven thousand, nine hundred eleven".