1221001123213 has 2 divisors, whose sum is σ = 1221001123214. Its totient is φ = 1221001123212.

The previous prime is 1221001123201. The next prime is 1221001123219. The reversal of 1221001123213 is 3123211001221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1126735544484 + 94265578729 = 1061478^2 + 307027^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221001123213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221001123219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610500561606 + 610500561607.

It is an arithmetic number, because the mean of its divisors is an integer number (610500561607).

Almost surely, 2^{1221001123213} is an apocalyptic number.

It is an amenable number.

1221001123213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221001123213 is an equidigital number, since it uses as much as digits as its factorization.

1221001123213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 1221001123213 its reverse (3123211001221), we get a palindrome (4344212124434).

The spelling of 1221001123213 in words is "one trillion, two hundred twenty-one billion, one million, one hundred twenty-three thousand, two hundred thirteen".