211022221021 has 4 divisors (see below), whose sum is σ = 213111550044. Its totient is φ = 208932892000.

The previous prime is 211022221013. The next prime is 211022221031. The reversal of 211022221021 is 120122220112.

It is a happy number.

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 179839605625 + 31182615396 = 424075^2 + 176586^2 .

It is a cyclic number.

It is not a de Polignac number, because 211022221021 - 2³ = 211022221013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211022220986 and 211022221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211022221031) 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, 1044664360 + ... + 1044664561.

It is an arithmetic number, because the mean of its divisors is an integer number (53277887511).

Almost surely, 2^211022221021 is an apocalyptic number.

It is an amenable number.

211022221021 is a deficient number, since it is larger than the sum of its proper divisors (2089329023).

211022221021 is a wasteful number, since it uses less digits than its factorization.

211022221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2089329022.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 211022221021 its reverse (120122220112), we get a palindrome (331144441133).

Subtracting from 211022221021 its reverse (120122220112), we obtain a palindrome (90900000909).

The spelling of 211022221021 in words is "two hundred eleven billion, twenty-two million, two hundred twenty-one thousand, twenty-one".