686347944 has 128 divisors (see below), whose sum is σ = 1862784000. Its totient is φ = 210069504.

The previous prime is 686347889. The next prime is 686347973. The reversal of 686347944 is 449743686.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2609557 + ... + 2609819.

It is an arithmetic number, because the mean of its divisors is an integer number (14553000).

Almost surely, 2^686347944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686347944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (931392000).

686347944 is an abundant number, since it is smaller than the sum of its proper divisors (1176436056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686347944 is a wasteful number, since it uses less digits than its factorization.

686347944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447 (or 443 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 51.

The square root of 686347944 is about 26198.2431472036. The cubic root of 686347944 is about 882.0938192372.

The spelling of 686347944 in words is "six hundred eighty-six million, three hundred forty-seven thousand, nine hundred forty-four".