685995666 has 16 divisors (see below), whose sum is σ = 1375734144. Its totient is φ = 228041424.

The previous prime is 685995649. The next prime is 685995697. The reversal of 685995666 is 666599586.

685995666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 153565 + ... + 157968.

It is an arithmetic number, because the mean of its divisors is an integer number (85983384).

Almost surely, 2^685995666 is an apocalyptic number.

685995666 is an abundant number, since it is smaller than the sum of its proper divisors (689738478).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685995666 is a wasteful number, since it uses less digits than its factorization.

685995666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311905.

The product of its digits is 20995200, while the sum is 60.

The square root of 685995666 is about 26191.5189708425. The cubic root of 685995666 is about 881.9428776103.

The spelling of 685995666 in words is "six hundred eighty-five million, nine hundred ninety-five thousand, six hundred sixty-six".