685861291 has 4 divisors (see below), whose sum is σ = 686102400. Its totient is φ = 685620184.

The previous prime is 685861283. The next prime is 685861303. The reversal of 685861291 is 192168586.

685861291 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 685861291 - 2³ = 685861283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685861201) 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, 116236 + ... + 121993.

It is an arithmetic number, because the mean of its divisors is an integer number (171525600).

Almost surely, 2^685861291 is an apocalyptic number.

685861291 is a deficient number, since it is larger than the sum of its proper divisors (241109).

685861291 is a wasteful number, since it uses less digits than its factorization.

685861291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241108.

The product of its digits is 207360, while the sum is 46.

The square root of 685861291 is about 26188.9536064349. The cubic root of 685861291 is about 881.8852879301.

The spelling of 685861291 in words is "six hundred eighty-five million, eight hundred sixty-one thousand, two hundred ninety-one".