1321200321 has 32 divisors (see below), whose sum is σ = 2133350400. Its totient is φ = 710467200.

The previous prime is 1321200311. The next prime is 1321200379. The reversal of 1321200321 is 1230021231.

It is not a de Polignac number, because 1321200321 - 2⁷ = 1321200193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321200321.

It is not an unprimeable number, because it can be changed into a prime (1321200311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49285 + ... + 71213.

It is an arithmetic number, because the mean of its divisors is an integer number (66667200).

Almost surely, 2^1321200321 is an apocalyptic number.

It is an amenable number.

1321200321 is a deficient number, since it is larger than the sum of its proper divisors (812150079).

1321200321 is a wasteful number, since it uses less digits than its factorization.

1321200321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22109.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1321200321 is about 36348.3193696765. The cubic root of 1321200321 is about 1097.2937111911.

Adding to 1321200321 its reverse (1230021231), we get a palindrome (2551221552).

The spelling of 1321200321 in words is "one billion, three hundred twenty-one million, two hundred thousand, three hundred twenty-one".