686548639 has 8 divisors (see below), whose sum is σ = 811683360. Its totient is φ = 568178016.

The previous prime is 686548619. The next prime is 686548657. The reversal of 686548639 is 936845686.

It is a happy number.

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

It is not a de Polignac number, because 686548639 - 2⁹ = 686548127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 686548639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686548609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1690804 + ... + 1691209.

It is an arithmetic number, because the mean of its divisors is an integer number (101460420).

Almost surely, 2^686548639 is an apocalyptic number.

686548639 is a deficient number, since it is larger than the sum of its proper divisors (125134721).

686548639 is a wasteful number, since it uses less digits than its factorization.

686548639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3382049.

The product of its digits is 7464960, while the sum is 55.

The square root of 686548639 is about 26202.0731813343. The cubic root of 686548639 is about 882.1797885419.

The spelling of 686548639 in words is "six hundred eighty-six million, five hundred forty-eight thousand, six hundred thirty-nine".