681322321 has 4 divisors (see below), whose sum is σ = 681616692. Its totient is φ = 681027952.

The previous prime is 681322283. The next prime is 681322331. The reversal of 681322321 is 123223186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 129072321 + 552250000 = 11361^2 + 23500^2 .

It is a cyclic number.

It is not a de Polignac number, because 681322321 - 2⁷ = 681322193 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 681322321.

It is not an unprimeable number, because it can be changed into a prime (681322331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143686 + ... + 148351.

It is an arithmetic number, because the mean of its divisors is an integer number (170404173).

Almost surely, 2^681322321 is an apocalyptic number.

It is an amenable number.

681322321 is a deficient number, since it is larger than the sum of its proper divisors (294371).

681322321 is a wasteful number, since it uses less digits than its factorization.

681322321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294370.

The product of its digits is 3456, while the sum is 28.

The square root of 681322321 is about 26102.1516546050. The cubic root of 681322321 is about 879.9355673382.

The spelling of 681322321 in words is "six hundred eighty-one million, three hundred twenty-two thousand, three hundred twenty-one".