666779013 has 8 divisors (see below), whose sum is σ = 987820800. Its totient is φ = 444519324.

The previous prime is 666778979. The next prime is 666779021. The reversal of 666779013 is 310977666.

It is not a de Polignac number, because 666779013 - 2¹⁷ = 666647941 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666779013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666779033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12347733 + ... + 12347786.

It is an arithmetic number, because the mean of its divisors is an integer number (123477600).

Almost surely, 2^666779013 is an apocalyptic number.

It is an amenable number.

666779013 is a deficient number, since it is larger than the sum of its proper divisors (321041787).

666779013 is a wasteful number, since it uses less digits than its factorization.

666779013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24695528 (or 24695522 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 45.

The square root of 666779013 is about 25822.0644604571. The cubic root of 666779013 is about 873.6295337611.

The spelling of 666779013 in words is "six hundred sixty-six million, seven hundred seventy-nine thousand, thirteen".