681567329 has 4 divisors (see below), whose sum is σ = 697417776. Its totient is φ = 665716884.

The previous prime is 681567319. The next prime is 681567331. The reversal of 681567329 is 923765186.

681567329 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 923765186 = 2 ⋅461882593.

It is a de Polignac number, because none of the positive numbers 2^k-681567329 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (681567319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7925159 + ... + 7925244.

It is an arithmetic number, because the mean of its divisors is an integer number (174354444).

Almost surely, 2^681567329 is an apocalyptic number.

It is an amenable number.

681567329 is a deficient number, since it is larger than the sum of its proper divisors (15850447).

681567329 is a wasteful number, since it uses less digits than its factorization.

681567329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15850446.

The product of its digits is 544320, while the sum is 47.

The square root of 681567329 is about 26106.8444856900. The cubic root of 681567329 is about 880.0410315751.

The spelling of 681567329 in words is "six hundred eighty-one million, five hundred sixty-seven thousand, three hundred twenty-nine".