681296321 has 2 divisors, whose sum is σ = 681296322. Its totient is φ = 681296320.

The previous prime is 681296311. The next prime is 681296327. The reversal of 681296321 is 123692186.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 616975921 + 64320400 = 24839^2 + 8020^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681296321 is a prime.

It is a Chen prime.

It is equal to p_35333678 and since 681296321 and 35333678 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (681296327) 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 as a sum of consecutive naturals, namely, 340648160 + 340648161.

It is an arithmetic number, because the mean of its divisors is an integer number (340648161).

Almost surely, 2^681296321 is an apocalyptic number.

It is an amenable number.

681296321 is a deficient number, since it is larger than the sum of its proper divisors (1).

681296321 is an equidigital number, since it uses as much as digits as its factorization.

681296321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 38.

The square root of 681296321 is about 26101.6536066204. The cubic root of 681296321 is about 879.9243740967.

The spelling of 681296321 in words is "six hundred eighty-one million, two hundred ninety-six thousand, three hundred twenty-one".