321220445 has 64 divisors (see below), whose sum is σ = 495161856. Its totient is φ = 194641920.

The previous prime is 321220433. The next prime is 321220477. The reversal of 321220445 is 544022123.

It is a happy number.

It is not a de Polignac number, because 321220445 - 2⁴ = 321220429 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 321220445.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1249757 + ... + 1250013.

It is an arithmetic number, because the mean of its divisors is an integer number (7736904).

Almost surely, 2^321220445 is an apocalyptic number.

321220445 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

321220445 is a deficient number, since it is larger than the sum of its proper divisors (173941411).

321220445 is a wasteful number, since it uses less digits than its factorization.

321220445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 321220445 is about 17922.6238313479. The cubic root of 321220445 is about 684.8588303756.

Adding to 321220445 its reverse (544022123), we get a palindrome (865242568).

The spelling of 321220445 in words is "three hundred twenty-one million, two hundred twenty thousand, four hundred forty-five".