321404981 has 2 divisors, whose sum is σ = 321404982. Its totient is φ = 321404980.

The previous prime is 321404957. The next prime is 321404983. The reversal of 321404981 is 189404123.

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., 276058225 + 45346756 = 16615^2 + 6734^2 .

It is a cyclic number.

It is not a de Polignac number, because 321404981 - 2¹⁴ = 321388597 is a prime.

It is a super-2 number, since 2×321404981² = 206602323623220722, which contains 22 as substring.

Together with 321404983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321404983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160702490 + 160702491.

It is an arithmetic number, because the mean of its divisors is an integer number (160702491).

Almost surely, 2^321404981 is an apocalyptic number.

It is an amenable number.

321404981 is a deficient number, since it is larger than the sum of its proper divisors (1).

321404981 is an equidigital number, since it uses as much as digits as its factorization.

321404981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 321404981 is about 17927.7712223243. The cubic root of 321404981 is about 684.9899520788.

The spelling of 321404981 in words is "three hundred twenty-one million, four hundred four thousand, nine hundred eighty-one".