1221331223201 has 2 divisors, whose sum is σ = 1221331223202. Its totient is φ = 1221331223200.

The previous prime is 1221331223087. The next prime is 1221331223207. The reversal of 1221331223201 is 1023221331221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 940219183201 + 281112040000 = 969649^2 + 530200^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221331223201 - 2³⁴ = 1204151354017 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221331223207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610665611600 + 610665611601.

It is an arithmetic number, because the mean of its divisors is an integer number (610665611601).

Almost surely, 2^{1221331223201} is an apocalyptic number.

It is an amenable number.

1221331223201 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221331223201 is an equidigital number, since it uses as much as digits as its factorization.

1221331223201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 1221331223201 its reverse (1023221331221), we get a palindrome (2244552554422).

The spelling of 1221331223201 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one million, two hundred twenty-three thousand, two hundred one".