685670391 has 24 divisors (see below), whose sum is σ = 1133452320. Its totient is φ = 391274496.

The previous prime is 685670383. The next prime is 685670407. The reversal of 685670391 is 193076586.

It is a happy number.

It is not a de Polignac number, because 685670391 - 2³ = 685670383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685670311) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41371 + ... + 55523.

It is an arithmetic number, because the mean of its divisors is an integer number (47227180).

Almost surely, 2^685670391 is an apocalyptic number.

685670391 is a deficient number, since it is larger than the sum of its proper divisors (447781929).

685670391 is a wasteful number, since it uses less digits than its factorization.

685670391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14935 (or 14932 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 685670391 is about 26185.3086863608. The cubic root of 685670391 is about 881.8034601487.

The spelling of 685670391 in words is "six hundred eighty-five million, six hundred seventy thousand, three hundred ninety-one".