1131222221 has 2 divisors, whose sum is σ = 1131222222. Its totient is φ = 1131222220.

The previous prime is 1131222217. The next prime is 1131222229. The reversal of 1131222221 is 1222221311.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1129632100 + 1590121 = 33610^2 + 1261^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131222221 - 2² = 1131222217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1131222221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1131222229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565611110 + 565611111.

It is an arithmetic number, because the mean of its divisors is an integer number (565611111).

Almost surely, 2^1131222221 is an apocalyptic number.

It is an amenable number.

1131222221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131222221 is an equidigital number, since it uses as much as digits as its factorization.

1131222221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 17.

The square root of 1131222221 is about 33633.6471557873. The cubic root of 1131222221 is about 1041.9558304571.

Adding to 1131222221 its reverse (1222221311), we get a palindrome (2353443532).

It can be divided in two parts, 11312 and 22221, that added together give a palindrome (33533).

The spelling of 1131222221 in words is "one billion, one hundred thirty-one million, two hundred twenty-two thousand, two hundred twenty-one".