1213111105 has 4 divisors (see below), whose sum is σ = 1455733332. Its totient is φ = 970488880.

The previous prime is 1213111099. The next prime is 1213111121. The reversal of 1213111105 is 5011113121.

It is a happy number.

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 335292721 + 877818384 = 18311^2 + 29628^2 .

It is not a de Polignac number, because 1213111105 - 2⁹ = 1213110593 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 121311106 + ... + 121311115.

It is an arithmetic number, because the mean of its divisors is an integer number (363933333).

Almost surely, 2^1213111105 is an apocalyptic number.

It is an amenable number.

1213111105 is a deficient number, since it is larger than the sum of its proper divisors (242622227).

1213111105 is an equidigital number, since it uses as much as digits as its factorization.

1213111105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242622226.

The product of its (nonzero) digits is 30, while the sum is 16.

The square root of 1213111105 is about 34829.7445439957. The cubic root of 1213111105 is about 1066.5147335142.

Adding to 1213111105 its reverse (5011113121), we get a palindrome (6224224226).

The spelling of 1213111105 in words is "one billion, two hundred thirteen million, one hundred eleven thousand, one hundred five".