1123312121 has 2 divisors, whose sum is σ = 1123312122. Its totient is φ = 1123312120.

The previous prime is 1123312109. The next prime is 1123312159. The reversal of 1123312121 is 1212133211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 666207721 + 457104400 = 25811^2 + 21380^2 .

It is an emirp because it is prime and its reverse (1212133211) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1123312121 - 2²⁶ = 1056203257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1123312121.

It is not a weakly prime, because it can be changed into another prime (1123312181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 561656060 + 561656061.

It is an arithmetic number, because the mean of its divisors is an integer number (561656061).

Almost surely, 2^1123312121 is an apocalyptic number.

It is an amenable number.

1123312121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1123312121 is an equidigital number, since it uses as much as digits as its factorization.

1123312121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72, while the sum is 17.

The square root of 1123312121 is about 33515.8488032155. The cubic root of 1123312121 is about 1039.5215134330.

Adding to 1123312121 its reverse (1212133211), we get a palindrome (2335445332).

The spelling of 1123312121 in words is "one billion, one hundred twenty-three million, three hundred twelve thousand, one hundred twenty-one".