111212022220021 has 4 divisors (see below), whose sum is σ = 111216002492844. Its totient is φ = 111208041947200.

The previous prime is 111212022220001. The next prime is 111212022220031. The reversal of 111212022220021 is 120022220212111.

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 52148401318225 + 59063620901796 = 7221385^2 + 7685286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111212022220021 is a prime.

It is a super-2 number, since 2×111212022220021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111212022220001) 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, 1990094500 + ... + 1990150381.

It is an arithmetic number, because the mean of its divisors is an integer number (27804000623211).

Almost surely, 2^{111212022220021} is an apocalyptic number.

It is an amenable number.

111212022220021 is a deficient number, since it is larger than the sum of its proper divisors (3980272823).

111212022220021 is an equidigital number, since it uses as much as digits as its factorization.

111212022220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980272822.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 111212022220021 its reverse (120022220212111), we get a palindrome (231234242432132).

The spelling of 111212022220021 in words is "one hundred eleven trillion, two hundred twelve billion, twenty-two million, two hundred twenty thousand, twenty-one".