1213223111 has 4 divisors (see below), whose sum is σ = 1213998912. Its totient is φ = 1212447312.

The previous prime is 1213223107. The next prime is 1213223117. The reversal of 1213223111 is 1113223121.

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 1213223111 - 2² = 1213223107 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 1213223111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213223117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385550 + ... + 388683.

It is an arithmetic number, because the mean of its divisors is an integer number (303499728).

Almost surely, 2^1213223111 is an apocalyptic number.

1213223111 is a deficient number, since it is larger than the sum of its proper divisors (775801).

1213223111 is an equidigital number, since it uses as much as digits as its factorization.

1213223111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775800.

The product of its digits is 72, while the sum is 17.

The square root of 1213223111 is about 34831.3524141685. The cubic root of 1213223111 is about 1066.5475561118.

Adding to 1213223111 its reverse (1113223121), we get a palindrome (2326446232).

The spelling of 1213223111 in words is "one billion, two hundred thirteen million, two hundred twenty-three thousand, one hundred eleven".