21210021324 has 18 divisors (see below), whose sum is σ = 53614220660. Its totient is φ = 7070007096.

The previous prime is 21210021323. The next prime is 21210021337. The reversal of 21210021324 is 42312001212.

It is a happy number.

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

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

It is a junction number, because it is equal to n+sod(n) for n = 21210021297 and 21210021306.

It is not an unprimeable number, because it can be changed into a prime (21210021323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 294583594 + ... + 294583665.

Almost surely, 2^21210021324 is an apocalyptic number.

It is an amenable number.

21210021324 is an abundant number, since it is smaller than the sum of its proper divisors (32404199336).

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

21210021324 is a wasteful number, since it uses less digits than its factorization.

21210021324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589167269 (or 589167264 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21210021324 its reverse (42312001212), we get a palindrome (63522022536).

The spelling of 21210021324 in words is "twenty-one billion, two hundred ten million, twenty-one thousand, three hundred twenty-four".