121100111111 has 6 divisors (see below), whose sum is σ = 140871557880. Its totient is φ = 103800095196.

The previous prime is 121100111081. The next prime is 121100111113. The reversal of 121100111111 is 111111001121.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-121100111111 is a prime.

It is a super-2 number, since 2×121100111111² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121100111092 and 121100111101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121100111113) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1235715371 + ... + 1235715468.

It is an arithmetic number, because the mean of its divisors is an integer number (23478592980).

Almost surely, 2^121100111111 is an apocalyptic number.

121100111111 is a deficient number, since it is larger than the sum of its proper divisors (19771446769).

121100111111 is an equidigital number, since it uses as much as digits as its factorization.

121100111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2471430853 (or 2471430846 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 121100111111 its reverse (111111001121), we get a palindrome (232211112232).

The spelling of 121100111111 in words is "one hundred twenty-one billion, one hundred million, one hundred eleven thousand, one hundred eleven".