685718739 has 6 divisors (see below), whose sum is σ = 990482636. Its totient is φ = 457145820.

The previous prime is 685718731. The next prime is 685718753. The reversal of 685718739 is 937817586.

685718739 is a `hidden beast` number, since 68 + 571 + 8 + 7 + 3 + 9 = 666.

It is not a de Polignac number, because 685718739 - 2³ = 685718731 is a prime.

It is a super-3 number, since 3×685718739³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685718731) 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, 38095477 + ... + 38095494.

Almost surely, 2^685718739 is an apocalyptic number.

685718739 is a deficient number, since it is larger than the sum of its proper divisors (304763897).

685718739 is a wasteful number, since it uses less digits than its factorization.

685718739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76190977 (or 76190974 counting only the distinct ones).

The product of its digits is 2540160, while the sum is 54.

The square root of 685718739 is about 26186.2318595097. The cubic root of 685718739 is about 881.8241855741.

The spelling of 685718739 in words is "six hundred eighty-five million, seven hundred eighteen thousand, seven hundred thirty-nine".