685618739 has 8 divisors (see below), whose sum is σ = 738568992. Its totient is φ = 632698560.

The previous prime is 685618699. The next prime is 685618793. The reversal of 685618739 is 937816586.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-685618739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685618039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67967 + ... + 77399.

It is an arithmetic number, because the mean of its divisors is an integer number (92321124).

Almost surely, 2^685618739 is an apocalyptic number.

685618739 is a deficient number, since it is larger than the sum of its proper divisors (52950253).

685618739 is a wasteful number, since it uses less digits than its factorization.

685618739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15037.

The product of its digits is 2177280, while the sum is 53.

The square root of 685618739 is about 26184.3223895521. The cubic root of 685618739 is about 881.7813173151.

The spelling of 685618739 in words is "six hundred eighty-five million, six hundred eighteen thousand, seven hundred thirty-nine".