1228636111 has 4 divisors (see below), whose sum is σ = 1228753800. Its totient is φ = 1228518424.

The previous prime is 1228636099. The next prime is 1228636133. The reversal of 1228636111 is 1116368221.

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 1228636111 - 2²⁷ = 1094418383 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 (1228636141) 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, 41476 + ... + 64633.

It is an arithmetic number, because the mean of its divisors is an integer number (307188450).

Almost surely, 2^1228636111 is an apocalyptic number.

1228636111 is a deficient number, since it is larger than the sum of its proper divisors (117689).

1228636111 is a wasteful number, since it uses less digits than its factorization.

1228636111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117688.

The product of its digits is 3456, while the sum is 31.

The square root of 1228636111 is about 35051.9059538850. The cubic root of 1228636111 is about 1071.0450996563.

The spelling of 1228636111 in words is "one billion, two hundred twenty-eight million, six hundred thirty-six thousand, one hundred eleven".