681745 has 8 divisors (see below), whose sum is σ = 832320. Its totient is φ = 535920.

The previous prime is 681731. The next prime is 681763. The reversal of 681745 is 547186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 681745 - 2¹³ = 673553 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 861 + ... + 1450.

It is an arithmetic number, because the mean of its divisors is an integer number (104040).

2⁶⁸¹⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

681745 is a deficient number, since it is larger than the sum of its proper divisors (150575).

681745 is a wasteful number, since it uses less digits than its factorization.

681745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2375.

The product of its digits is 6720, while the sum is 31.

The square root of 681745 is about 825.6785088641. The cubic root of 681745 is about 88.0117494642.

The spelling of 681745 in words is "six hundred eighty-one thousand, seven hundred forty-five".