681878 has 4 divisors (see below), whose sum is σ = 1022820. Its totient is φ = 340938.

The previous prime is 681841. The next prime is 681883. The reversal of 681878 is 878186.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170468 + ... + 170471.

It is an arithmetic number, because the mean of its divisors is an integer number (255705).

2⁶⁸¹⁸⁷⁸ is an apocalyptic number.

681878 is a deficient number, since it is larger than the sum of its proper divisors (340942).

681878 is a wasteful number, since it uses less digits than its factorization.

681878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340941.

The product of its digits is 21504, while the sum is 38.

The square root of 681878 is about 825.7590447582. The cubic root of 681878 is about 88.0174724259.

The spelling of 681878 in words is "six hundred eighty-one thousand, eight hundred seventy-eight".