1331221231 has 2 divisors, whose sum is σ = 1331221232. Its totient is φ = 1331221230.

The previous prime is 1331221121. The next prime is 1331221273. The reversal of 1331221231 is 1321221331.

It is a strong prime.

It is an emirp because it is prime and its reverse (1321221331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1331221231 - 2²¹ = 1329124079 is a prime.

It is a super-2 number, since 2×1331221231² = 3544299931730310722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1331221199 and 1331221208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331221291) 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 as a sum of consecutive naturals, namely, 665610615 + 665610616.

It is an arithmetic number, because the mean of its divisors is an integer number (665610616).

Almost surely, 2^1331221231 is an apocalyptic number.

1331221231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331221231 is an equidigital number, since it uses as much as digits as its factorization.

1331221231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 19.

The square root of 1331221231 is about 36485.9045523062. The cubic root of 1331221231 is about 1100.0609418027.

Adding to 1331221231 its reverse (1321221331), we get a palindrome (2652442562).

It can be divided in two parts, 13312 and 21231, that added together give a palindrome (34543).

The spelling of 1331221231 in words is "one billion, three hundred thirty-one million, two hundred twenty-one thousand, two hundred thirty-one".