686513855 has 8 divisors (see below), whose sum is σ = 826450512. Its totient is φ = 547455168.

The previous prime is 686513851. The next prime is 686513899. The reversal of 686513855 is 558315686.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 686513855 - 2² = 686513851 is a prime.

It is a super-2 number, since 2×686513855² = 942602546213922050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686513851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217769 + ... + 220898.

It is an arithmetic number, because the mean of its divisors is an integer number (103306314).

Almost surely, 2^686513855 is an apocalyptic number.

686513855 is a deficient number, since it is larger than the sum of its proper divisors (139936657).

686513855 is a wasteful number, since it uses less digits than its factorization.

686513855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438985.

The product of its digits is 864000, while the sum is 47.

The square root of 686513855 is about 26201.4094086559. The cubic root of 686513855 is about 882.1648897383.

The spelling of 686513855 in words is "six hundred eighty-six million, five hundred thirteen thousand, eight hundred fifty-five".