665987308711 has 4 divisors (see below), whose sum is σ = 665989350624. Its totient is φ = 665985266800.

The previous prime is 665987308691. The next prime is 665987308729. The reversal of 665987308711 is 117803789566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665987308711 - 2⁷ = 665987308583 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665987308711.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665987302711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409750 + ... + 1224691.

It is an arithmetic number, because the mean of its divisors is an integer number (166497337656).

Almost surely, 2^665987308711 is an apocalyptic number.

665987308711 is a deficient number, since it is larger than the sum of its proper divisors (2041913).

665987308711 is a wasteful number, since it uses less digits than its factorization.

665987308711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2041912.

The product of its (nonzero) digits is 15240960, while the sum is 61.

The spelling of 665987308711 in words is "six hundred sixty-five billion, nine hundred eighty-seven million, three hundred eight thousand, seven hundred eleven".