211111222021 has 4 divisors (see below), whose sum is σ = 241269968032. Its totient is φ = 180952476012.

The previous prime is 211111221977. The next prime is 211111222027. The reversal of 211111222021 is 120222111112.

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 not a de Polignac number, because 211111222021 - 2¹¹ = 211111219973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211111221986 and 211111222004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211111222027) 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, 15079372995 + ... + 15079373008.

It is an arithmetic number, because the mean of its divisors is an integer number (60317492008).

Almost surely, 2^211111222021 is an apocalyptic number.

It is an amenable number.

211111222021 is a deficient number, since it is larger than the sum of its proper divisors (30158746011).

211111222021 is an equidigital number, since it uses as much as digits as its factorization.

211111222021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30158746010.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 211111222021 its reverse (120222111112), we get a palindrome (331333333133).

The spelling of 211111222021 in words is "two hundred eleven billion, one hundred eleven million, two hundred twenty-two thousand, twenty-one".