1221120111 has 4 divisors (see below), whose sum is σ = 1628160152. Its totient is φ = 814080072.

The previous prime is 1221120107. The next prime is 1221120119. The reversal of 1221120111 is 1110211221.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1221120111 - 2² = 1221120107 is a prime.

It is a super-2 number, since 2×1221120111² = 2982268650977304642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221120119) 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, 203520016 + ... + 203520021.

It is an arithmetic number, because the mean of its divisors is an integer number (407040038).

Almost surely, 2^1221120111 is an apocalyptic number.

1221120111 is a deficient number, since it is larger than the sum of its proper divisors (407040041).

1221120111 is an equidigital number, since it uses as much as digits as its factorization.

1221120111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407040040.

The product of its (nonzero) digits is 8, while the sum is 12.

The square root of 1221120111 is about 34944.5290567780. The cubic root of 1221120111 is about 1068.8566443016.

Adding to 1221120111 its reverse (1110211221), we get a palindrome (2331331332).

The spelling of 1221120111 in words is "one billion, two hundred twenty-one million, one hundred twenty thousand, one hundred eleven".