1221331323 has 16 divisors (see below), whose sum is σ = 1725403680. Its totient is φ = 765805056.

The previous prime is 1221331313. The next prime is 1221331327. The reversal of 1221331323 is 3231331221.

It is not a de Polignac number, because 1221331323 - 2⁵ = 1221331291 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221331323.

It is not an unprimeable number, because it can be changed into a prime (1221331327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76173 + ... + 90801.

It is an arithmetic number, because the mean of its divisors is an integer number (107837730).

Almost surely, 2^1221331323 is an apocalyptic number.

1221331323 is a deficient number, since it is larger than the sum of its proper divisors (504072357).

1221331323 is a wasteful number, since it uses less digits than its factorization.

1221331323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16286.

The product of its digits is 648, while the sum is 21.

The square root of 1221331323 is about 34947.5510300793. The cubic root of 1221331323 is about 1068.9182659589.

Adding to 1221331323 its reverse (3231331221), we get a palindrome (4452662544).

The spelling of 1221331323 in words is "one billion, two hundred twenty-one million, three hundred thirty-one thousand, three hundred twenty-three".