681854 has 4 divisors (see below), whose sum is σ = 1022784. Its totient is φ = 340926.

The previous prime is 681841. The next prime is 681883. The reversal of 681854 is 458186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 458186 = 2 ⋅229093.

It is a self number, because there is not a number n which added to its sum of digits gives 681854.

It is a congruent number.

It is an unprimeable number.

681854 is an untouchable number, because it is not equal to the sum of proper divisors of any 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, 170462 + ... + 170465.

It is an arithmetic number, because the mean of its divisors is an integer number (255696).

2⁶⁸¹⁸⁵⁴ is an apocalyptic number.

681854 is a deficient number, since it is larger than the sum of its proper divisors (340930).

681854 is a wasteful number, since it uses less digits than its factorization.

681854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340929.

The product of its digits is 7680, while the sum is 32.

The square root of 681854 is about 825.7445125461. The cubic root of 681854 is about 88.0164397661.

The spelling of 681854 in words is "six hundred eighty-one thousand, eight hundred fifty-four".