665880878 has 16 divisors (see below), whose sum is σ = 1132267920. Its totient is φ = 291154176.

The previous prime is 665880869. The next prime is 665880911. The reversal of 665880878 is 878088566.

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, 673475 + ... + 674462.

It is an arithmetic number, because the mean of its divisors is an integer number (70766745).

Almost surely, 2^665880878 is an apocalyptic number.

665880878 is a deficient number, since it is larger than the sum of its proper divisors (466387042).

665880878 is a wasteful number, since it uses less digits than its factorization.

665880878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1347971.

The product of its (nonzero) digits is 5160960, while the sum is 56.

The square root of 665880878 is about 25804.6677560475. The cubic root of 665880878 is about 873.2371049825.

The spelling of 665880878 in words is "six hundred sixty-five million, eight hundred eighty thousand, eight hundred seventy-eight".