681391261 has 8 divisors (see below), whose sum is σ = 711278784. Its totient is φ = 651525600.

The previous prime is 681391231. The next prime is 681391303. The reversal of 681391261 is 162193186.

681391261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 681391261 - 2¹¹ = 681389213 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 681391261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681391231) 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, 114561 + ... + 120361.

It is an arithmetic number, because the mean of its divisors is an integer number (88909848).

Almost surely, 2^681391261 is an apocalyptic number.

It is an amenable number.

681391261 is a deficient number, since it is larger than the sum of its proper divisors (29887523).

681391261 is a wasteful number, since it uses less digits than its factorization.

681391261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10931.

The product of its digits is 15552, while the sum is 37.

The square root of 681391261 is about 26103.4722019888. The cubic root of 681391261 is about 879.9652452700.

The spelling of 681391261 in words is "six hundred eighty-one million, three hundred ninety-one thousand, two hundred sixty-one".