21213232211 has 4 divisors (see below), whose sum is σ = 21214395000. Its totient is φ = 21212069424.

The previous prime is 21213232177. The next prime is 21213232217. The reversal of 21213232211 is 11223231212.

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 21213232211 - 2¹⁴ = 21213215827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21213232217) 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, 553586 + ... + 590663.

It is an arithmetic number, because the mean of its divisors is an integer number (5303598750).

Almost surely, 2^21213232211 is an apocalyptic number.

21213232211 is a deficient number, since it is larger than the sum of its proper divisors (1162789).

21213232211 is a wasteful number, since it uses less digits than its factorization.

21213232211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1162788.

The product of its digits is 288, while the sum is 20.

Adding to 21213232211 its reverse (11223231212), we get a palindrome (32436463423).

Subtracting from 21213232211 its reverse (11223231212), we obtain a palindrome (9990000999).

The spelling of 21213232211 in words is "twenty-one billion, two hundred thirteen million, two hundred thirty-two thousand, two hundred eleven".