1231212133 has 4 divisors (see below), whose sum is σ = 1232315500. Its totient is φ = 1230108768.

The previous prime is 1231212127. The next prime is 1231212161. The reversal of 1231212133 is 3312121321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3312121321 = 1627 ⋅2035723.

It can be written as a sum of positive squares in 2 ways, for example, as 605061604 + 626150529 = 24598^2 + 25023^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231212133 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 1231212133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231212533) 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, 550008 + ... + 552241.

It is an arithmetic number, because the mean of its divisors is an integer number (308078875).

Almost surely, 2^1231212133 is an apocalyptic number.

It is an amenable number.

1231212133 is a deficient number, since it is larger than the sum of its proper divisors (1103367).

1231212133 is a wasteful number, since it uses less digits than its factorization.

1231212133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103366.

The product of its digits is 216, while the sum is 19.

The square root of 1231212133 is about 35088.6325324884. The cubic root of 1231212133 is about 1071.7931133040.

Adding to 1231212133 its reverse (3312121321), we get a palindrome (4543333454).

It can be divided in two parts, 123121213 and 3, that added together give a square (123121216 = 11096²).

The spelling of 1231212133 in words is "one billion, two hundred thirty-one million, two hundred twelve thousand, one hundred thirty-three".