21202122211 has 4 divisors (see below), whose sum is σ = 22318023400. Its totient is φ = 20086221024.

The previous prime is 21202122197. The next prime is 21202122233. The reversal of 21202122211 is 11222120212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21202122211 - 2⁷ = 21202122083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202122911) 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, 557950566 + ... + 557950603.

It is an arithmetic number, because the mean of its divisors is an integer number (5579505850).

Almost surely, 2^21202122211 is an apocalyptic number.

21202122211 is a deficient number, since it is larger than the sum of its proper divisors (1115901189).

21202122211 is a wasteful number, since it uses less digits than its factorization.

21202122211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115901188.

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

Adding to 21202122211 its reverse (11222120212), we get a palindrome (32424242423).

The spelling of 21202122211 in words is "twenty-one billion, two hundred two million, one hundred twenty-two thousand, two hundred eleven".