321402421 has 2 divisors, whose sum is σ = 321402422. Its totient is φ = 321402420.

The previous prime is 321402383. The next prime is 321402439. The reversal of 321402421 is 124204123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193599396 + 127803025 = 13914^2 + 11305^2 .

It is an emirp because it is prime and its reverse (124204123) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 321402421 - 2⁷ = 321402293 is a prime.

It is a super-2 number, since 2×321402421² = 206599032449322482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321402821) 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, 160701210 + 160701211.

It is an arithmetic number, because the mean of its divisors is an integer number (160701211).

Almost surely, 2^321402421 is an apocalyptic number.

It is an amenable number.

321402421 is a deficient number, since it is larger than the sum of its proper divisors (1).

321402421 is an equidigital number, since it uses as much as digits as its factorization.

321402421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 321402421 is about 17927.6998245731. The cubic root of 321402421 is about 684.9881334190.

Adding to 321402421 its reverse (124204123), we get a palindrome (445606544).

The spelling of 321402421 in words is "three hundred twenty-one million, four hundred two thousand, four hundred twenty-one".