1211513113 has 4 divisors (see below), whose sum is σ = 1211914548. Its totient is φ = 1211111680.

The previous prime is 1211513099. The next prime is 1211513159. The reversal of 1211513113 is 3113151121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 983261449 + 228251664 = 31357^2 + 15108^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211513113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211513213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196156 + ... + 202237.

It is an arithmetic number, because the mean of its divisors is an integer number (302978637).

Almost surely, 2^1211513113 is an apocalyptic number.

It is an amenable number.

1211513113 is a deficient number, since it is larger than the sum of its proper divisors (401435).

1211513113 is an equidigital number, since it uses as much as digits as its factorization.

1211513113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401434.

The product of its digits is 90, while the sum is 19.

The square root of 1211513113 is about 34806.7969368053. The cubic root of 1211513113 is about 1066.0462326255.

Adding to 1211513113 its reverse (3113151121), we get a palindrome (4324664234).

The spelling of 1211513113 in words is "one billion, two hundred eleven million, five hundred thirteen thousand, one hundred thirteen".