326221981 has 2 divisors, whose sum is σ = 326221982. Its totient is φ = 326221980.

The previous prime is 326221937. The next prime is 326221997. The reversal of 326221981 is 189122623.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 275228100 + 50993881 = 16590^2 + 7141^2 .

It is a cyclic number.

It is not a de Polignac number, because 326221981 - 2⁷ = 326221853 is a prime.

It is a super-2 number, since 2×326221981² = 212841561775128722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (326231981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163110990 + 163110991.

It is an arithmetic number, because the mean of its divisors is an integer number (163110991).

Almost surely, 2^326221981 is an apocalyptic number.

It is an amenable number.

326221981 is a deficient number, since it is larger than the sum of its proper divisors (1).

326221981 is an equidigital number, since it uses as much as digits as its factorization.

326221981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 326221981 is about 18061.6162344348. The cubic root of 326221981 is about 688.3950522365.

The spelling of 326221981 in words is "three hundred twenty-six million, two hundred twenty-one thousand, nine hundred eighty-one".