686463778 has 32 divisors (see below), whose sum is σ = 1382532480. Its totient is φ = 246879360.

The previous prime is 686463733. The next prime is 686463781. The reversal of 686463778 is 877364686.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169443 + ... + 173446.

It is an arithmetic number, because the mean of its divisors is an integer number (43204140).

Almost surely, 2^686463778 is an apocalyptic number.

686463778 is an abundant number, since it is smaller than the sum of its proper divisors (696068702).

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

686463778 is a wasteful number, since it uses less digits than its factorization.

686463778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342922.

The product of its digits is 8128512, while the sum is 55.

The square root of 686463778 is about 26200.4537746963. The cubic root of 686463778 is about 882.1434397001.

It can be divided in two parts, 686463 and 778, that added together give a square (687241 = 829²).

The spelling of 686463778 in words is "six hundred eighty-six million, four hundred sixty-three thousand, seven hundred seventy-eight".