686255656 has 8 divisors (see below), whose sum is σ = 1286729370. Its totient is φ = 343127824.

The previous prime is 686255653. The next prime is 686255659. The reversal of 686255656 is 656552686.

686255656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (686255653) and next prime (686255659).

It can be written as a sum of positive squares in only one way, i.e., 588838756 + 97416900 = 24266^2 + 9870^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (686255653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42890971 + ... + 42890986.

Almost surely, 2^686255656 is an apocalyptic number.

It is an amenable number.

686255656 is a deficient number, since it is larger than the sum of its proper divisors (600473714).

686255656 is a wasteful number, since it uses less digits than its factorization.

686255656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85781963 (or 85781959 counting only the distinct ones).

The product of its digits is 2592000, while the sum is 49.

The square root of 686255656 is about 26196.4817485097. The cubic root of 686255656 is about 882.0542813109.

The spelling of 686255656 in words is "six hundred eighty-six million, two hundred fifty-five thousand, six hundred fifty-six".