321831161 has 2 divisors, whose sum is σ = 321831162. Its totient is φ = 321831160.

The previous prime is 321831149. The next prime is 321831187. The reversal of 321831161 is 161138123.

It is an a-pointer prime, because the next prime (321831187) can be obtained adding 321831161 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 314707600 + 7123561 = 17740^2 + 2669^2 .

It is a cyclic number.

It is not a de Polignac number, because 321831161 - 2²⁶ = 254722297 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 321831161.

It is not a weakly prime, because it can be changed into another prime (321831061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160915580 + 160915581.

It is an arithmetic number, because the mean of its divisors is an integer number (160915581).

Almost surely, 2^321831161 is an apocalyptic number.

It is an amenable number.

321831161 is a deficient number, since it is larger than the sum of its proper divisors (1).

321831161 is an equidigital number, since it uses as much as digits as its factorization.

321831161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

The square root of 321831161 is about 17939.6533132611. The cubic root of 321831161 is about 685.2925817810.

Subtracting from 321831161 its sum of digits (26), we obtain a triangular number (321831135 = T₂₅₃₇₀).

Adding to 321831161 its reverse (161138123), we get a palindrome (482969284).

The spelling of 321831161 in words is "three hundred twenty-one million, eight hundred thirty-one thousand, one hundred sixty-one".