321311989 has 2 divisors, whose sum is σ = 321311990. Its totient is φ = 321311988.

The previous prime is 321311971. The next prime is 321311999. The reversal of 321311989 is 989113123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190026225 + 131285764 = 13785^2 + 11458^2 .

It is a cyclic number.

It is not a de Polignac number, because 321311989 - 2¹⁵ = 321279221 is a prime.

It is a super-2 number, since 2×321311989² = 206482788550272242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321311999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160655994 + 160655995.

It is an arithmetic number, because the mean of its divisors is an integer number (160655995).

Almost surely, 2^321311989 is an apocalyptic number.

It is an amenable number.

321311989 is a deficient number, since it is larger than the sum of its proper divisors (1).

321311989 is an equidigital number, since it uses as much as digits as its factorization.

321311989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 321311989 is about 17925.1775165548. The cubic root of 321311989 is about 684.9238830655.

The spelling of 321311989 in words is "three hundred twenty-one million, three hundred eleven thousand, nine hundred eighty-nine".