21231322212 has 24 divisors (see below), whose sum is σ = 49542138016. Its totient is φ = 7076766528.

The previous prime is 21231322193. The next prime is 21231322213. The reversal of 21231322212 is 21222313212.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21231322213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 404928 + ... + 454344.

Almost surely, 2^21231322212 is an apocalyptic number.

It is an amenable number.

21231322212 is an abundant number, since it is smaller than the sum of its proper divisors (28310815804).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21231322212 is a wasteful number, since it uses less digits than its factorization.

21231322212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85227 (or 85225 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

Adding to 21231322212 its reverse (21222313212), we get a palindrome (42453635424).

The spelling of 21231322212 in words is "twenty-one billion, two hundred thirty-one million, three hundred twenty-two thousand, two hundred twelve".