1221333331 has 2 divisors, whose sum is σ = 1221333332. Its totient is φ = 1221333330.

The previous prime is 1221333307. The next prime is 1221333341. The reversal of 1221333331 is 1333331221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221333331 - 2²³ = 1212944723 is a prime.

It is a super-2 number, since 2×1221333331² = 2983310210823111122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221333341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610666665 + 610666666.

It is an arithmetic number, because the mean of its divisors is an integer number (610666666).

Almost surely, 2^1221333331 is an apocalyptic number.

1221333331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221333331 is an equidigital number, since it uses as much as digits as its factorization.

1221333331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 22.

The square root of 1221333331 is about 34947.5797588331. The cubic root of 1221333331 is about 1068.9188517641.

Adding to 1221333331 its reverse (1333331221), we get a palindrome (2554664552).

The spelling of 1221333331 in words is "one billion, two hundred twenty-one million, three hundred thirty-three thousand, three hundred thirty-one".