111212020021 has 4 divisors (see below), whose sum is σ = 113798346112. Its totient is φ = 108625693932.

The previous prime is 111212019983. The next prime is 111212020033. The reversal of 111212020021 is 120020212111.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 111212020021 - 2²⁷ = 111077802293 is a prime.

It is a super-2 number, since 2×111212020021² (a number of 23 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 = 111212019983 and 111212020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111212020081) 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, 1293162981 + ... + 1293163066.

It is an arithmetic number, because the mean of its divisors is an integer number (28449586528).

Almost surely, 2^111212020021 is an apocalyptic number.

It is an amenable number.

111212020021 is a deficient number, since it is larger than the sum of its proper divisors (2586326091).

111212020021 is an equidigital number, since it uses as much as digits as its factorization.

111212020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2586326090.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 111212020021 its reverse (120020212111), we get a palindrome (231232232132).

The spelling of 111212020021 in words is "one hundred eleven billion, two hundred twelve million, twenty thousand, twenty-one".