1221003101 has 2 divisors, whose sum is σ = 1221003102. Its totient is φ = 1221003100.

The previous prime is 1221003089. The next prime is 1221003131. The reversal of 1221003101 is 1013001221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1206172900 + 14830201 = 34730^2 + 3851^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221003101 - 2¹⁰ = 1221002077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221003131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610501550 + 610501551.

It is an arithmetic number, because the mean of its divisors is an integer number (610501551).

Almost surely, 2^1221003101 is an apocalyptic number.

It is an amenable number.

1221003101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221003101 is an equidigital number, since it uses as much as digits as its factorization.

1221003101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 1221003101 is about 34942.8547917883. The cubic root of 1221003101 is about 1068.8225032673.

Adding to 1221003101 its reverse (1013001221), we get a palindrome (2234004322).

The spelling of 1221003101 in words is "one billion, two hundred twenty-one million, three thousand, one hundred one".