1223131121 has 4 divisors (see below), whose sum is σ = 1223898612. Its totient is φ = 1222363632.

The previous prime is 1223131081. The next prime is 1223131127. The reversal of 1223131121 is 1211313221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1211313221 = 6563 ⋅184567.

It can be written as a sum of positive squares in 2 ways, for example, as 105165025 + 1117966096 = 10255^2 + 33436^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1223131121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1223131121.

It is not an unprimeable number, because it can be changed into a prime (1223131127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 381350 + ... + 384543.

It is an arithmetic number, because the mean of its divisors is an integer number (305974653).

Almost surely, 2^1223131121 is an apocalyptic number.

It is an amenable number.

1223131121 is a deficient number, since it is larger than the sum of its proper divisors (767491).

1223131121 is an equidigital number, since it uses as much as digits as its factorization.

1223131121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767490.

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

The square root of 1223131121 is about 34973.2915379722. The cubic root of 1223131121 is about 1069.4430737873.

Adding to 1223131121 its reverse (1211313221), we get a palindrome (2434444342).

The spelling of 1223131121 in words is "one billion, two hundred twenty-three million, one hundred thirty-one thousand, one hundred twenty-one".