121111216129 has 4 divisors (see below), whose sum is σ = 121112771584. Its totient is φ = 121109660676.

The previous prime is 121111216123. The next prime is 121111216147. The reversal of 121111216129 is 921612111121.

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 121111216129 - 2²⁵ = 121077661697 is a prime.

It is a super-3 number, since 3×121111216129³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121111216097 and 121111216106.

It is not an unprimeable number, because it can be changed into a prime (121111216123) 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, 654417 + ... + 818830.

It is an arithmetic number, because the mean of its divisors is an integer number (30278192896).

Almost surely, 2^121111216129 is an apocalyptic number.

It is an amenable number.

121111216129 is a deficient number, since it is larger than the sum of its proper divisors (1555455).

121111216129 is an equidigital number, since it uses as much as digits as its factorization.

121111216129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555454.

The product of its digits is 432, while the sum is 28.

The spelling of 121111216129 in words is "one hundred twenty-one billion, one hundred eleven million, two hundred sixteen thousand, one hundred twenty-nine".