681920 has 28 divisors (see below), whose sum is σ = 1624584. Its totient is φ = 272640.

The previous prime is 681913. The next prime is 681931. The reversal of 681920 is 29186.

It is a self number, because there is not a number n which added to its sum of digits gives 681920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746 + ... + 1385.

2⁶⁸¹⁹²⁰ is an apocalyptic number.

It is an amenable number.

681920 is an abundant number, since it is smaller than the sum of its proper divisors (942664).

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

681920 is a wasteful number, since it uses less digits than its factorization.

681920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2148 (or 2138 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 681920 is about 825.7844755140. The cubic root of 681920 is about 88.0192795224.

The spelling of 681920 in words is "six hundred eighty-one thousand, nine hundred twenty".