11111211212021 has 4 divisors (see below), whose sum is σ = 11185783099500. Its totient is φ = 11036639324544.

The previous prime is 11111211211987. The next prime is 11111211212039. The reversal of 11111211212021 is 12021211211111.

11111211212021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 5271207319921 + 5840003892100 = 2295911^2 + 2416610^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11111211212021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111211212921) 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, 37285943516 + ... + 37285943813.

It is an arithmetic number, because the mean of its divisors is an integer number (2796445774875).

Almost surely, 2^{11111211212021} is an apocalyptic number.

It is an amenable number.

11111211212021 is a deficient number, since it is larger than the sum of its proper divisors (74571887479).

11111211212021 is an equidigital number, since it uses as much as digits as its factorization.

11111211212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74571887478.

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

Adding to 11111211212021 its reverse (12021211211111), we get a palindrome (23132422423132).

The spelling of 11111211212021 in words is "eleven trillion, one hundred eleven billion, two hundred eleven million, two hundred twelve thousand, twenty-one".