1221313121233 has 2 divisors, whose sum is σ = 1221313121234. Its totient is φ = 1221313121232.

The previous prime is 1221313121213. The next prime is 1221313121239. The reversal of 1221313121233 is 3321213131221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 707099355664 + 514213765569 = 840892^2 + 717087^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221313121233 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221313121198 and 1221313121207.

It is not a weakly prime, because it can be changed into another prime (1221313121239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610656560616 + 610656560617.

It is an arithmetic number, because the mean of its divisors is an integer number (610656560617).

Almost surely, 2^{1221313121233} is an apocalyptic number.

It is an amenable number.

1221313121233 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221313121233 is an equidigital number, since it uses as much as digits as its factorization.

1221313121233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 25.

Adding to 1221313121233 its reverse (3321213131221), we get a palindrome (4542526252454).

The spelling of 1221313121233 in words is "one trillion, two hundred twenty-one billion, three hundred thirteen million, one hundred twenty-one thousand, two hundred thirty-three".