111211220021 has 16 divisors (see below), whose sum is σ = 124398058176. Its totient is φ = 98541840000.

The previous prime is 111211219969. The next prime is 111211220093. The reversal of 111211220021 is 120022112111.

It is a cyclic number.

It is not a de Polignac number, because 111211220021 - 2³⁰ = 110137478197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111211219978 and 111211220005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111211220821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 362306 + ... + 594716.

It is an arithmetic number, because the mean of its divisors is an integer number (7774878636).

Almost surely, 2^111211220021 is an apocalyptic number.

111211220021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111211220021 is a deficient number, since it is larger than the sum of its proper divisors (13186838155).

111211220021 is a wasteful number, since it uses less digits than its factorization.

111211220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233524.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 111211220021 its reverse (120022112111), we get a palindrome (231233332132).

The spelling of 111211220021 in words is "one hundred eleven billion, two hundred eleven million, two hundred twenty thousand, twenty-one".