21003121332 has 72 divisors (see below), whose sum is σ = 54564461952. Its totient is φ = 6807888000.

The previous prime is 21003121289. The next prime is 21003121357. The reversal of 21003121332 is 23312130012.

21003121332 is a `hidden beast` number, since 21 + 0 + 0 + 312 + 1 + 332 = 666.

It is a super-2 number, since 2×21003121332² (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 congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 429957 + ... + 476307.

Almost surely, 2^21003121332 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21003121332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27282230976).

21003121332 is an abundant number, since it is smaller than the sum of its proper divisors (33561340620).

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

21003121332 is a wasteful number, since it uses less digits than its factorization.

21003121332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46709 (or 46704 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21003121332 its reverse (23312130012), we get a palindrome (44315251344).

The spelling of 21003121332 in words is "twenty-one billion, three million, one hundred twenty-one thousand, three hundred thirty-two".