1213240121 has 2 divisors, whose sum is σ = 1213240122. Its totient is φ = 1213240120.

The previous prime is 1213240111. The next prime is 1213240123. The reversal of 1213240121 is 1210423121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1093228096 + 120012025 = 33064^2 + 10955^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213240121 - 2⁶ = 1213240057 is a prime.

Together with 1213240123, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1213240121.

It is not a weakly prime, because it can be changed into another prime (1213240123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606620060 + 606620061.

It is an arithmetic number, because the mean of its divisors is an integer number (606620061).

Almost surely, 2^1213240121 is an apocalyptic number.

It is an amenable number.

1213240121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213240121 is an equidigital number, since it uses as much as digits as its factorization.

1213240121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1213240121 is about 34831.5965898780. The cubic root of 1213240121 is about 1066.5525406001.

Adding to 1213240121 its reverse (1210423121), we get a palindrome (2423663242).

The spelling of 1213240121 in words is "one billion, two hundred thirteen million, two hundred forty thousand, one hundred twenty-one".