1220311111 has 4 divisors (see below), whose sum is σ = 1220844672. Its totient is φ = 1219777552.

The previous prime is 1220311109. The next prime is 1220311117. The reversal of 1220311111 is 1111130221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1111130221 = 181 ⋅6138841.

It is a cyclic number.

It is not a de Polignac number, because 1220311111 - 2¹ = 1220311109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220311091 and 1220311100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220311117) 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, 263335 + ... + 267928.

It is an arithmetic number, because the mean of its divisors is an integer number (305211168).

Almost surely, 2^1220311111 is an apocalyptic number.

1220311111 is a deficient number, since it is larger than the sum of its proper divisors (533561).

1220311111 is an equidigital number, since it uses as much as digits as its factorization.

1220311111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533560.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1220311111 is about 34932.9516502685. The cubic root of 1220311111 is about 1068.6205506678.

Adding to 1220311111 its reverse (1111130221), we get a palindrome (2331441332).

The spelling of 1220311111 in words is "one billion, two hundred twenty million, three hundred eleven thousand, one hundred eleven".