681570 has 24 divisors (see below), whose sum is σ = 1772316. Its totient is φ = 181728.

The previous prime is 681563. The next prime is 681589. The reversal of 681570 is 75186.

It can be written as a sum of positive squares in 2 ways, for example, as 622521 + 59049 = 789^2 + 243^2 .

It is an Ulam number.

It is a nialpdrome in base 16.

It is an unprimeable number.

681570 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3697 + ... + 3876.

2⁶⁸¹⁵⁷⁰ is an apocalyptic number.

681570 is an abundant number, since it is smaller than the sum of its proper divisors (1090746).

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

681570 is a wasteful number, since it uses less digits than its factorization.

681570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7586 (or 7583 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 681570 is about 825.5725286127. The cubic root of 681570 is about 88.0042181174.

The spelling of 681570 in words is "six hundred eighty-one thousand, five hundred seventy".