1221203117 has 2 divisors, whose sum is σ = 1221203118. Its totient is φ = 1221203116.

The previous prime is 1221203089. The next prime is 1221203129. The reversal of 1221203117 is 7113021221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1162741801 + 58461316 = 34099^2 + 7646^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221203117 - 2⁸ = 1221202861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221203917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610601558 + 610601559.

It is an arithmetic number, because the mean of its divisors is an integer number (610601559).

Almost surely, 2^1221203117 is an apocalyptic number.

It is an amenable number.

1221203117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221203117 is an equidigital number, since it uses as much as digits as its factorization.

1221203117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 1221203117 is about 34945.7167189342. The cubic root of 1221203117 is about 1068.8808623682.

Adding to 1221203117 its reverse (7113021221), we get a palindrome (8334224338).

The spelling of 1221203117 in words is "one billion, two hundred twenty-one million, two hundred three thousand, one hundred seventeen".