111212110012121 has 4 divisors (see below), whose sum is σ = 113035259356644. Its totient is φ = 109388960667600.

The previous prime is 111212110012051. The next prime is 111212110012123. The reversal of 111212110012121 is 121210011212111.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9989676816025 + 101222433196096 = 3160645^2 + 10060936^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111212110012121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 111212110012121.

It is not an unprimeable number, because it can be changed into a prime (111212110012123) 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, 911574672170 + ... + 911574672291.

It is an arithmetic number, because the mean of its divisors is an integer number (28258814839161).

Almost surely, 2^{111212110012121} is an apocalyptic number.

It is an amenable number.

111212110012121 is a deficient number, since it is larger than the sum of its proper divisors (1823149344523).

111212110012121 is an equidigital number, since it uses as much as digits as its factorization.

111212110012121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823149344522.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 111212110012121 its reverse (121210011212111), we get a palindrome (232422121224232).

The spelling of 111212110012121 in words is "one hundred eleven trillion, two hundred twelve billion, one hundred ten million, twelve thousand, one hundred twenty-one".