685681407 has 6 divisors (see below), whose sum is σ = 990428712. Its totient is φ = 457120932.

The previous prime is 685681393. The next prime is 685681411. The reversal of 685681407 is 704186586.

It is a happy number.

It is not a de Polignac number, because 685681407 - 2⁷ = 685681279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685681207) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38093403 + ... + 38093420.

It is an arithmetic number, because the mean of its divisors is an integer number (165071452).

Almost surely, 2^685681407 is an apocalyptic number.

685681407 is a deficient number, since it is larger than the sum of its proper divisors (304747305).

685681407 is a wasteful number, since it uses less digits than its factorization.

685681407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76186829 (or 76186826 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 685681407 is about 26185.5190324729. The cubic root of 685681407 is about 881.8081824832.

The spelling of 685681407 in words is "six hundred eighty-five million, six hundred eighty-one thousand, four hundred seven".