686448656 has 20 divisors (see below), whose sum is σ = 1342427472. Its totient is φ = 340015776.

The previous prime is 686448643. The next prime is 686448703. The reversal of 686448656 is 656844686.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 686448598 and 686448607.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198770 + ... + 202193.

Almost surely, 2^686448656 is an apocalyptic number.

It is an amenable number.

686448656 is a deficient number, since it is larger than the sum of its proper divisors (655978816).

686448656 is a wasteful number, since it uses less digits than its factorization.

686448656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401078 (or 401072 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 53.

The square root of 686448656 is about 26200.1651903189. The cubic root of 686448656 is about 882.1369621206.

The spelling of 686448656 in words is "six hundred eighty-six million, four hundred forty-eight thousand, six hundred fifty-six".