1211111323111 has 4 divisors (see below), whose sum is σ = 1212126505632. Its totient is φ = 1210096140592.

The previous prime is 1211111323109. The next prime is 1211111323157. The reversal of 1211111323111 is 1113231111121.

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 1211111323111 - 2¹ = 1211111323109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211111323181) 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, 507589471 + ... + 507591856.

It is an arithmetic number, because the mean of its divisors is an integer number (303031626408).

Almost surely, 2^{1211111323111} is an apocalyptic number.

1211111323111 is a deficient number, since it is larger than the sum of its proper divisors (1015182521).

1211111323111 is a wasteful number, since it uses less digits than its factorization.

1211111323111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015182520.

The product of its digits is 36, while the sum is 19.

Adding to 1211111323111 its reverse (1113231111121), we get a palindrome (2324342434232).

The spelling of 1211111323111 in words is "one trillion, two hundred eleven billion, one hundred eleven million, three hundred twenty-three thousand, one hundred eleven".