685660431 has 16 divisors (see below), whose sum is σ = 940880000. Its totient is φ = 443825568.

The previous prime is 685660421. The next prime is 685660433. The reversal of 685660431 is 134066586.

It is not a de Polignac number, because 685660431 - 2²⁵ = 652105999 is a prime.

It is a super-2 number, since 2×685660431² = 940260453278211522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 685660431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685660433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49200 + ... + 61578.

It is an arithmetic number, because the mean of its divisors is an integer number (58805000).

Almost surely, 2^685660431 is an apocalyptic number.

685660431 is a deficient number, since it is larger than the sum of its proper divisors (255219569).

685660431 is a wasteful number, since it uses less digits than its factorization.

685660431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12918.

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 685660431 is about 26185.1185026916. The cubic root of 685660431 is about 881.7991904563.

The spelling of 685660431 in words is "six hundred eighty-five million, six hundred sixty thousand, four hundred thirty-one".