1221321133213 has 2 divisors, whose sum is σ = 1221321133214. Its totient is φ = 1221321133212.

The previous prime is 1221321133139. The next prime is 1221321133223. The reversal of 1221321133213 is 3123311231221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1162390172164 + 58930961049 = 1078142^2 + 242757^2 .

It is an emirp because it is prime and its reverse (3123311231221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221321133213 - 2¹⁷ = 1221321002141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221321133223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610660566606 + 610660566607.

It is an arithmetic number, because the mean of its divisors is an integer number (610660566607).

Almost surely, 2^{1221321133213} is an apocalyptic number.

It is an amenable number.

1221321133213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221321133213 is an equidigital number, since it uses as much as digits as its factorization.

1221321133213 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 1221321133213 its reverse (3123311231221), we get a palindrome (4344632364434).

The spelling of 1221321133213 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, one hundred thirty-three thousand, two hundred thirteen".