321220387 has 2 divisors, whose sum is σ = 321220388. Its totient is φ = 321220386.

The previous prime is 321220381. The next prime is 321220397. The reversal of 321220387 is 783022123.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 321220387 - 2¹⁵ = 321187619 is a prime.

It is not a weakly prime, because it can be changed into another prime (321220381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160610193 + 160610194.

It is an arithmetic number, because the mean of its divisors is an integer number (160610194).

Almost surely, 2^321220387 is an apocalyptic number.

321220387 is a deficient number, since it is larger than the sum of its proper divisors (1).

321220387 is an equidigital number, since it uses as much as digits as its factorization.

321220387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 321220387 is about 17922.6222132812. The cubic root of 321220387 is about 684.8587891559.

The spelling of 321220387 in words is "three hundred twenty-one million, two hundred twenty thousand, three hundred eighty-seven".