321721343 has 2 divisors, whose sum is σ = 321721344. Its totient is φ = 321721342.

The previous prime is 321721261. The next prime is 321721349. The reversal of 321721343 is 343127123.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 321721343 - 2²⁸ = 53285887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321721349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160860671 + 160860672.

It is an arithmetic number, because the mean of its divisors is an integer number (160860672).

Almost surely, 2^321721343 is an apocalyptic number.

321721343 is a deficient number, since it is larger than the sum of its proper divisors (1).

321721343 is an equidigital number, since it uses as much as digits as its factorization.

321721343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 26.

The square root of 321721343 is about 17936.5922906220. The cubic root of 321721343 is about 685.2146257681.

Adding to 321721343 its reverse (343127123), we get a palindrome (664848466).

The spelling of 321721343 in words is "three hundred twenty-one million, seven hundred twenty-one thousand, three hundred forty-three".