121220111 has 4 divisors (see below), whose sum is σ = 121343424. Its totient is φ = 121096800.

The previous prime is 121220107. The next prime is 121220117. The reversal of 121220111 is 111022121.

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 121220111 - 2² = 121220107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121220092 and 121220101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220117) 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, 60170 + ... + 62151.

It is an arithmetic number, because the mean of its divisors is an integer number (30335856).

Almost surely, 2^121220111 is an apocalyptic number.

121220111 is a deficient number, since it is larger than the sum of its proper divisors (123313).

121220111 is an equidigital number, since it uses as much as digits as its factorization.

121220111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123312.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 121220111 is about 11010.0004995459. Note that the first 3 decimals coincide. The cubic root of 121220111 is about 494.9084767699.

Subtracting from 121220111 its sum of digits (11), we obtain a square (121220100 = 11010²).

Adding to 121220111 its reverse (111022121), we get a palindrome (232242232).

The spelling of 121220111 in words is "one hundred twenty-one million, two hundred twenty thousand, one hundred eleven".