1221535241 has 2 divisors, whose sum is σ = 1221535242. Its totient is φ = 1221535240.

The previous prime is 1221535199. The next prime is 1221535243. The reversal of 1221535241 is 1425351221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1159062025 + 62473216 = 34045^2 + 7904^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221535241 - 2⁶ = 1221535177 is a prime.

Together with 1221535243, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221535241.

It is not a weakly prime, because it can be changed into another prime (1221535243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610767620 + 610767621.

It is an arithmetic number, because the mean of its divisors is an integer number (610767621).

Almost surely, 2^1221535241 is an apocalyptic number.

It is an amenable number.

1221535241 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221535241 is an equidigital number, since it uses as much as digits as its factorization.

1221535241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 26.

The square root of 1221535241 is about 34950.4683945723. The cubic root of 1221535241 is about 1068.9777528322.

Adding to 1221535241 its reverse (1425351221), we get a palindrome (2646886462).

The spelling of 1221535241 in words is "one billion, two hundred twenty-one million, five hundred thirty-five thousand, two hundred forty-one".