321399989 has 2 divisors, whose sum is σ = 321399990. Its totient is φ = 321399988.

The previous prime is 321399983. The next prime is 321399997. The reversal of 321399989 is 989993123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212197489 + 109202500 = 14567^2 + 10450^2 .

It is a cyclic number.

It is not a de Polignac number, because 321399989 - 2⁴ = 321399973 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 321399989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321399983) 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, 160699994 + 160699995.

It is an arithmetic number, because the mean of its divisors is an integer number (160699995).

Almost surely, 2^321399989 is an apocalyptic number.

It is an amenable number.

321399989 is a deficient number, since it is larger than the sum of its proper divisors (1).

321399989 is an equidigital number, since it uses as much as digits as its factorization.

321399989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 944784, while the sum is 53.

The square root of 321399989 is about 17927.6319964462. The cubic root of 321399989 is about 684.9864056833.

The spelling of 321399989 in words is "three hundred twenty-one million, three hundred ninety-nine thousand, nine hundred eighty-nine".