21020022211 has 4 divisors (see below), whose sum is σ = 21020318424. Its totient is φ = 21019726000.

The previous prime is 21020022209. The next prime is 21020022241. The reversal of 21020022211 is 11222002012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21020022211 - 2¹ = 21020022209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020022191 and 21020022200.

It is not an unprimeable number, because it can be changed into a prime (21020022241) 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, 28671 + ... + 207031.

It is an arithmetic number, because the mean of its divisors is an integer number (5255079606).

Almost surely, 2^21020022211 is an apocalyptic number.

21020022211 is a deficient number, since it is larger than the sum of its proper divisors (296213).

21020022211 is a wasteful number, since it uses less digits than its factorization.

21020022211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296212.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21020022211 its reverse (11222002012), we get a palindrome (32242024223).

The spelling of 21020022211 in words is "twenty-one billion, twenty million, twenty-two thousand, two hundred eleven".