681009581 has 16 divisors (see below), whose sum is σ = 831114240. Its totient is φ = 545408640.

The previous prime is 681009557. The next prime is 681009587. The reversal of 681009581 is 185900186.

681009581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 681009581 - 2¹⁴ = 680993197 is a prime.

It is a super-2 number, since 2×681009581² = 927548098827591122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681009587) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47816 + ... + 60401.

It is an arithmetic number, because the mean of its divisors is an integer number (51944640).

Almost surely, 2^681009581 is an apocalyptic number.

It is an amenable number.

681009581 is a deficient number, since it is larger than the sum of its proper divisors (150104659).

681009581 is a wasteful number, since it uses less digits than its factorization.

681009581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108284.

The product of its (nonzero) digits is 17280, while the sum is 38.

The square root of 681009581 is about 26096.1602731130. The cubic root of 681009581 is about 879.8009109709.

The spelling of 681009581 in words is "six hundred eighty-one million, nine thousand, five hundred eighty-one".