1221322331 has 4 divisors (see below), whose sum is σ = 1221407592. Its totient is φ = 1221237072.

The previous prime is 1221322253. The next prime is 1221322351. The reversal of 1221322331 is 1332231221.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1221322331 - 2¹⁸ = 1221060187 is a prime.

It is a super-2 number, since 2×1221322331² = 2983256472398547122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221322351) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 15305 + ... + 51738.

It is an arithmetic number, because the mean of its divisors is an integer number (305351898).

Almost surely, 2^1221322331 is an apocalyptic number.

1221322331 is a deficient number, since it is larger than the sum of its proper divisors (85261).

1221322331 is an equidigital number, since it uses as much as digits as its factorization.

1221322331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85260.

The product of its digits is 432, while the sum is 20.

The square root of 1221322331 is about 34947.4223799124. The cubic root of 1221322331 is about 1068.9156426640.

Adding to 1221322331 its reverse (1332231221), we get a palindrome (2553553552).

The spelling of 1221322331 in words is "one billion, two hundred twenty-one million, three hundred twenty-two thousand, three hundred thirty-one".