111212121220001 has 4 divisors (see below), whose sum is σ = 111356740364100. Its totient is φ = 111067502075904.

The previous prime is 111212121219977. The next prime is 111212121220009. The reversal of 111212121220001 is 100022121212111.

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 65785060418401 + 45427060801600 = 8110799^2 + 6739960^2 .

It is a cyclic number.

It is not a de Polignac number, because 111212121220001 - 2¹⁰ = 111212121218977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111212121220009) 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, 72309570896 + ... + 72309572433.

It is an arithmetic number, because the mean of its divisors is an integer number (27839185091025).

Almost surely, 2^{111212121220001} is an apocalyptic number.

It is an amenable number.

111212121220001 is a deficient number, since it is larger than the sum of its proper divisors (144619144099).

111212121220001 is an equidigital number, since it uses as much as digits as its factorization.

111212121220001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144619144098.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 111212121220001 its reverse (100022121212111), we get a palindrome (211234242432112).

The spelling of 111212121220001 in words is "one hundred eleven trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twenty thousand, one".