1213331291 has 4 divisors (see below), whose sum is σ = 1213466352. Its totient is φ = 1213196232.

The previous prime is 1213331263. The next prime is 1213331299. The reversal of 1213331291 is 1921333121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1213331291 - 2¹⁰ = 1213330267 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 1213331291.

It is not an unprimeable number, because it can be changed into a prime (1213331299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53015 + ... + 72368.

It is an arithmetic number, because the mean of its divisors is an integer number (303366588).

Almost surely, 2^1213331291 is an apocalyptic number.

1213331291 is a deficient number, since it is larger than the sum of its proper divisors (135061).

1213331291 is an equidigital number, since it uses as much as digits as its factorization.

1213331291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135060.

The product of its digits is 972, while the sum is 26.

The square root of 1213331291 is about 34832.9052908310. The cubic root of 1213331291 is about 1066.5792556083.

The spelling of 1213331291 in words is "one billion, two hundred thirteen million, three hundred thirty-one thousand, two hundred ninety-one".