121211100111 has 4 divisors (see below), whose sum is σ = 161614800152. Its totient is φ = 80807400072.

The previous prime is 121211100083. The next prime is 121211100133. The reversal of 121211100111 is 111001112121.

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

It is not a de Polignac number, because 121211100111 - 2⁷ = 121211099983 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 (121211100511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20201850016 + ... + 20201850021.

It is an arithmetic number, because the mean of its divisors is an integer number (40403700038).

Almost surely, 2^121211100111 is an apocalyptic number.

121211100111 is a deficient number, since it is larger than the sum of its proper divisors (40403700041).

121211100111 is an equidigital number, since it uses as much as digits as its factorization.

121211100111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40403700040.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 121211100111 its reverse (111001112121), we get a palindrome (232212212232).

The spelling of 121211100111 in words is "one hundred twenty-one billion, two hundred eleven million, one hundred thousand, one hundred eleven".