665878878566 has 16 divisors (see below), whose sum is σ = 1153715276880. Its totient is φ = 284867969280.

The previous prime is 665878878557. The next prime is 665878878667.

665878878566 is nontrivially palindromic in base 10.

665878878566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 890212031 + ... + 890212778.

It is an arithmetic number, because the mean of its divisors is an integer number (72107204805).

Almost surely, 2^665878878566 is an apocalyptic number.

665878878566 is a deficient number, since it is larger than the sum of its proper divisors (487836398314).

665878878566 is a wasteful number, since it uses less digits than its factorization.

665878878566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780424839.

The product of its digits is 6502809600, while the sum is 80.

The spelling of 665878878566 in words is "six hundred sixty-five billion, eight hundred seventy-eight million, eight hundred seventy-eight thousand, five hundred sixty-six".