111111211100021 has 24 divisors (see below), whose sum is σ = 123503110187520. Its totient is φ = 99876870593280.

The previous prime is 111111211099979. The next prime is 111111211100033. The reversal of 111111211100021 is 120001112111111.

It is not a de Polignac number, because 111111211100021 - 2³⁰ = 111110137358197 is a prime.

It is a super-2 number, since 2×111111211100021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111111211099969 and 111111211100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111211100081) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8403590 + ... + 17112648.

It is an arithmetic number, because the mean of its divisors is an integer number (5145962924480).

Almost surely, 2^{111111211100021} is an apocalyptic number.

111111211100021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111111211100021 is a deficient number, since it is larger than the sum of its proper divisors (12391899087499).

111111211100021 is a wasteful number, since it uses less digits than its factorization.

111111211100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8710265 (or 8710254 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 14.

Adding to 111111211100021 its reverse (120001112111111), we get a palindrome (231112323211132).

The spelling of 111111211100021 in words is "one hundred eleven trillion, one hundred eleven billion, two hundred eleven million, one hundred thousand, twenty-one".