686439936 has 240 divisors, whose sum is σ = 2439781344. Its totient is φ = 180928512.

The previous prime is 686439931. The next prime is 686439937. The reversal of 686439936 is 639934686.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686439931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 418510 + ... + 420146.

Almost surely, 2^686439936 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 686439936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1219890672).

686439936 is an abundant number, since it is smaller than the sum of its proper divisors (1753341408).

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

686439936 is a wasteful number, since it uses less digits than its factorization.

686439936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1681 (or 1662 counting only the distinct ones).

The product of its digits is 5038848, while the sum is 54.

The square root of 686439936 is about 26199.9987786259. The cubic root of 686439936 is about 882.1332268245.

The spelling of 686439936 in words is "six hundred eighty-six million, four hundred thirty-nine thousand, nine hundred thirty-six".