1216245435221 has 2 divisors, whose sum is σ = 1216245435222. Its totient is φ = 1216245435220.

The previous prime is 1216245435203. The next prime is 1216245435239. The reversal of 1216245435221 is 1225345426121.

It is a balanced prime because it is at equal distance from previous prime (1216245435203) and next prime (1216245435239).

It can be written as a sum of positive squares in only one way, i.e., 944920084900 + 271325350321 = 972070^2 + 520889^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216245435221 - 2³⁴ = 1199065566037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216245435241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608122717610 + 608122717611.

It is an arithmetic number, because the mean of its divisors is an integer number (608122717611).

Almost surely, 2^{1216245435221} is an apocalyptic number.

It is an amenable number.

1216245435221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216245435221 is an equidigital number, since it uses as much as digits as its factorization.

1216245435221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 115200, while the sum is 38.

The spelling of 1216245435221 in words is "one trillion, two hundred sixteen billion, two hundred forty-five million, four hundred thirty-five thousand, two hundred twenty-one".