121111211121 has 4 divisors (see below), whose sum is σ = 161481614832. Its totient is φ = 80740807412.

The previous prime is 121111211119. The next prime is 121111211129. The reversal of 121111211121 is 121112111121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121111211121 - 2¹ = 121111211119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121111211121.

It is not an unprimeable number, because it can be changed into a prime (121111211129) 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, 20185201851 + ... + 20185201856.

It is an arithmetic number, because the mean of its divisors is an integer number (40370403708).

Almost surely, 2^121111211121 is an apocalyptic number.

It is an amenable number.

121111211121 is a deficient number, since it is larger than the sum of its proper divisors (40370403711).

121111211121 is an equidigital number, since it uses as much as digits as its factorization.

121111211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40370403710.

The product of its digits is 8, while the sum is 15.

Adding to 121111211121 its reverse (121112111121), we get a palindrome (242223322242).

It can be divided in two parts, 1211 and 11211121, that multiplied together give a palindrome (13576667531).

The spelling of 121111211121 in words is "one hundred twenty-one billion, one hundred eleven million, two hundred eleven thousand, one hundred twenty-one".