21530322212 has 12 divisors (see below), whose sum is σ = 43060644480. Its totient is φ = 9227280936.

The previous prime is 21530322211. The next prime is 21530322223. The reversal of 21530322212 is 21222303512.

21530322212 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21530322211) 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, 384470012 + ... + 384470067.

It is an arithmetic number, because the mean of its divisors is an integer number (3588387040).

Almost surely, 2^21530322212 is an apocalyptic number.

It is an amenable number.

21530322212 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21530322212 is a wasteful number, since it uses less digits than its factorization.

21530322212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768940090 (or 768940088 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 21530322212 its reverse (21222303512), we get a palindrome (42752625724).

The spelling of 21530322212 in words is "twenty-one billion, five hundred thirty million, three hundred twenty-two thousand, two hundred twelve".