685891723 has 4 divisors (see below), whose sum is σ = 748245528. Its totient is φ = 623537920.

The previous prime is 685891693. The next prime is 685891757. The reversal of 685891723 is 327198586.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 685891723 - 2⁵ = 685891691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685891783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31176886 + ... + 31176907.

It is an arithmetic number, because the mean of its divisors is an integer number (187061382).

Almost surely, 2^685891723 is an apocalyptic number.

685891723 is a deficient number, since it is larger than the sum of its proper divisors (62353805).

685891723 is a wasteful number, since it uses less digits than its factorization.

685891723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62353804.

The product of its digits is 725760, while the sum is 49.

The square root of 685891723 is about 26189.5346083125. The cubic root of 685891723 is about 881.8983309640.

The spelling of 685891723 in words is "six hundred eighty-five million, eight hundred ninety-one thousand, seven hundred twenty-three".