681731009 has 8 divisors (see below), whose sum is σ = 687087360. Its totient is φ = 676396000.

The previous prime is 681731003. The next prime is 681731051. The reversal of 681731009 is 900137186.

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

It is a cyclic number.

It is not a de Polignac number, because 681731009 - 2⁴ = 681730993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 681731009.

It is not an unprimeable number, because it can be changed into a prime (681731003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62084 + ... + 72234.

It is an arithmetic number, because the mean of its divisors is an integer number (85885920).

Almost surely, 2^681731009 is an apocalyptic number.

It is an amenable number.

681731009 is a deficient number, since it is larger than the sum of its proper divisors (5356351).

681731009 is a wasteful number, since it uses less digits than its factorization.

681731009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10671.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 681731009 is about 26109.9791076132. The cubic root of 681731009 is about 880.1114739122. Note that the first 3 decimals are identical.

The spelling of 681731009 in words is "six hundred eighty-one million, seven hundred thirty-one thousand, nine".