685668431 has 16 divisors (see below), whose sum is σ = 812851200. Its totient is φ = 565903968.

The previous prime is 685668427. The next prime is 685668437. The reversal of 685668431 is 134866586.

It is not a de Polignac number, because 685668431 - 2² = 685668427 is a prime.

It is a super-2 number, since 2×685668431² = 940282394540003522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685668437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73340 + ... + 82158.

It is an arithmetic number, because the mean of its divisors is an integer number (50803200).

Almost surely, 2^685668431 is an apocalyptic number.

685668431 is a deficient number, since it is larger than the sum of its proper divisors (127182769).

685668431 is a wasteful number, since it uses less digits than its factorization.

685668431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9238.

The product of its digits is 829440, while the sum is 47.

The square root of 685668431 is about 26185.2712607680. The cubic root of 685668431 is about 881.8026199314.

The spelling of 685668431 in words is "six hundred eighty-five million, six hundred sixty-eight thousand, four hundred thirty-one".