686681194 has 4 divisors (see below), whose sum is σ = 1030021794. Its totient is φ = 343340596.

The previous prime is 686681189. The next prime is 686681213. The reversal of 686681194 is 491186686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 624350169 + 62331025 = 24987^2 + 7895^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171670297 + ... + 171670300.

Almost surely, 2^686681194 is an apocalyptic number.

686681194 is a deficient number, since it is larger than the sum of its proper divisors (343340600).

686681194 is a wasteful number, since it uses less digits than its factorization.

686681194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343340599.

The product of its digits is 497664, while the sum is 49.

The square root of 686681194 is about 26204.6025346694. The cubic root of 686681194 is about 882.2365603472.

The spelling of 686681194 in words is "six hundred eighty-six million, six hundred eighty-one thousand, one hundred ninety-four".