321420643 has 2 divisors, whose sum is σ = 321420644. Its totient is φ = 321420642.

The previous prime is 321420623. The next prime is 321420661. The reversal of 321420643 is 346024123.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 321420643 - 2⁵ = 321420611 is a prime.

It is a super-2 number, since 2×321420643² = 206622459493066898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (321420623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160710321 + 160710322.

It is an arithmetic number, because the mean of its divisors is an integer number (160710322).

Almost surely, 2^321420643 is an apocalyptic number.

321420643 is a deficient number, since it is larger than the sum of its proper divisors (1).

321420643 is an equidigital number, since it uses as much as digits as its factorization.

321420643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 321420643 is about 17928.2080253437. The cubic root of 321420643 is about 685.0010783722.

Adding to 321420643 its reverse (346024123), we get a palindrome (667444766).

The spelling of 321420643 in words is "three hundred twenty-one million, four hundred twenty thousand, six hundred forty-three".