111211220121 has 4 divisors (see below), whose sum is σ = 148281626832. Its totient is φ = 74140813412.

The previous prime is 111211220117. The next prime is 111211220149. The reversal of 111211220121 is 121022112111.

It is a happy number.

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 111211220121 - 2² = 111211220117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 111211220121.

It is not an unprimeable number, because it can be changed into a prime (111211220171) 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, 18535203351 + ... + 18535203356.

It is an arithmetic number, because the mean of its divisors is an integer number (37070406708).

Almost surely, 2^111211220121 is an apocalyptic number.

It is an amenable number.

111211220121 is a deficient number, since it is larger than the sum of its proper divisors (37070406711).

111211220121 is an equidigital number, since it uses as much as digits as its factorization.

111211220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37070406710.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 111211220121 its reverse (121022112111), we get a palindrome (232233332232).

The spelling of 111211220121 in words is "one hundred eleven billion, two hundred eleven million, two hundred twenty thousand, one hundred twenty-one".