21212112132 has 18 divisors (see below), whose sum is σ = 53619505758. Its totient is φ = 7070704032.

The previous prime is 21212112121. The next prime is 21212112139. The reversal of 21212112132 is 23121121212.

It can be written as a sum of positive squares in only one way, i.e., 17083535616 + 4128576516 = 130704^2 + 64254^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×21212112132² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 (21212112139) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 294612633 + ... + 294612704.

It is an arithmetic number, because the mean of its divisors is an integer number (2978861431).

Almost surely, 2^21212112132 is an apocalyptic number.

It is an amenable number.

21212112132 is an abundant number, since it is smaller than the sum of its proper divisors (32407393626).

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

21212112132 is a wasteful number, since it uses less digits than its factorization.

21212112132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589225347 (or 589225342 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 21212112132 its reverse (23121121212), we get a palindrome (44333233344).

The spelling of 21212112132 in words is "twenty-one billion, two hundred twelve million, one hundred twelve thousand, one hundred thirty-two".