681994886 has 4 divisors (see below), whose sum is σ = 1022992332. Its totient is φ = 340997442.

The previous prime is 681994877. The next prime is 681994909. The reversal of 681994886 is 688499186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 688499186 = 2 ⋅344249593.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170498720 + ... + 170498723.

It is an arithmetic number, because the mean of its divisors is an integer number (255748083).

Almost surely, 2^681994886 is an apocalyptic number.

681994886 is a deficient number, since it is larger than the sum of its proper divisors (340997446).

681994886 is a wasteful number, since it uses less digits than its factorization.

681994886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340997445.

The product of its digits is 5971968, while the sum is 59.

The square root of 681994886 is about 26115.0318016272. The cubic root of 681994886 is about 880.2250139127.

The spelling of 681994886 in words is "six hundred eighty-one million, nine hundred ninety-four thousand, eight hundred eighty-six".