1221434213 has 2 divisors, whose sum is σ = 1221434214. Its totient is φ = 1221434212.

The previous prime is 1221434161. The next prime is 1221434219. The reversal of 1221434213 is 3124341221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1212571684 + 8862529 = 34822^2 + 2977^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221434213 is a prime.

It is a super-3 number, since 3×1221434213³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221434219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610717106 + 610717107.

It is an arithmetic number, because the mean of its divisors is an integer number (610717107).

Almost surely, 2^1221434213 is an apocalyptic number.

It is an amenable number.

1221434213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221434213 is an equidigital number, since it uses as much as digits as its factorization.

1221434213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 23.

The square root of 1221434213 is about 34949.0230621687. The cubic root of 1221434213 is about 1068.9482818140.

Adding to 1221434213 its reverse (3124341221), we get a palindrome (4345775434).

The spelling of 1221434213 in words is "one billion, two hundred twenty-one million, four hundred thirty-four thousand, two hundred thirteen".