685163391 has 16 divisors (see below), whose sum is σ = 997774848. Its totient is φ = 414761600.

The previous prime is 685163371. The next prime is 685163417. The reversal of 685163391 is 193361586.

It is a happy number.

It is not a de Polignac number, because 685163391 - 2⁹ = 685162879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685163371) 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, 17290 + ... + 40856.

It is an arithmetic number, because the mean of its divisors is an integer number (62360928).

Almost surely, 2^685163391 is an apocalyptic number.

685163391 is a deficient number, since it is larger than the sum of its proper divisors (312611457).

685163391 is a wasteful number, since it uses less digits than its factorization.

685163391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24462.

The product of its digits is 116640, while the sum is 42.

The square root of 685163391 is about 26175.6258950956. The cubic root of 685163391 is about 881.5860648337.

The spelling of 685163391 in words is "six hundred eighty-five million, one hundred sixty-three thousand, three hundred ninety-one".