686856402 has 64 divisors (see below), whose sum is σ = 1566051840. Its totient is φ = 223043328.

The previous prime is 686856377. The next prime is 686856421. The reversal of 686856402 is 204658686.

686856402 is a `hidden beast` number, since 6 + 86 + 8 + 564 + 0 + 2 = 666.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 702538 + ... + 703514.

It is an arithmetic number, because the mean of its divisors is an integer number (24469560).

Almost surely, 2^686856402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686856402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (783025920).

686856402 is an abundant number, since it is smaller than the sum of its proper divisors (879195438).

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

686856402 is a wasteful number, since it uses less digits than its factorization.

686856402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312 (or 1306 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The square root of 686856402 is about 26207.9453982948. The cubic root of 686856402 is about 882.3115887397.

The spelling of 686856402 in words is "six hundred eighty-six million, eight hundred fifty-six thousand, four hundred two".