1221001100213 has 2 divisors, whose sum is σ = 1221001100214. Its totient is φ = 1221001100212.

The previous prime is 1221001100197. The next prime is 1221001100233. The reversal of 1221001100213 is 3120011001221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1183619971249 + 37381128964 = 1087943^2 + 193342^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221001100213 - 2⁴ = 1221001100197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221001100233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610500550106 + 610500550107.

It is an arithmetic number, because the mean of its divisors is an integer number (610500550107).

Almost surely, 2^{1221001100213} is an apocalyptic number.

It is an amenable number.

1221001100213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221001100213 is an equidigital number, since it uses as much as digits as its factorization.

1221001100213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 1221001100213 its reverse (3120011001221), we get a palindrome (4341012101434).

The spelling of 1221001100213 in words is "one trillion, two hundred twenty-one billion, one million, one hundred thousand, two hundred thirteen".