1231033121 has 4 divisors (see below), whose sum is σ = 1303446852. Its totient is φ = 1158619392.

The previous prime is 1231033109. The next prime is 1231033127. The reversal of 1231033121 is 1213301321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1213301321 = 71 ⋅17088751.

It can be written as a sum of positive squares in 2 ways, for example, as 867597025 + 363436096 = 29455^2 + 19064^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231033121 - 2³⁰ = 157291297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 72413713 = 1231033121 / (1 + 2 + 3 + 1 + 0 + 3 + 3 + 1 + 2 + 1).

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 1231033121.

It is not an unprimeable number, because it can be changed into a prime (1231033127) 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, 36206840 + ... + 36206873.

It is an arithmetic number, because the mean of its divisors is an integer number (325861713).

Almost surely, 2^1231033121 is an apocalyptic number.

It is an amenable number.

1231033121 is a deficient number, since it is larger than the sum of its proper divisors (72413731).

1231033121 is an equidigital number, since it uses as much as digits as its factorization.

1231033121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72413730.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1231033121 is about 35086.0815851528. The cubic root of 1231033121 is about 1071.7411663586.

Adding to 1231033121 its reverse (1213301321), we get a palindrome (2444334442).

The spelling of 1231033121 in words is "one billion, two hundred thirty-one million, thirty-three thousand, one hundred twenty-one".