21253543332 has 96 divisors (see below), whose sum is σ = 59496407040. Its totient is φ = 5776911360.

The previous prime is 21253543331. The next prime is 21253543411. The reversal of 21253543332 is 23334535212.

It is a junction number, because it is equal to n+sod(n) for n = 21253543293 and 21253543302.

It is not an unprimeable number, because it can be changed into a prime (21253543331) 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 31 ways as a sum of consecutive naturals, for example, 84468 + ... + 222804.

It is an arithmetic number, because the mean of its divisors is an integer number (619754240).

Almost surely, 2^21253543332 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 21253543332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29748203520).

21253543332 is an abundant number, since it is smaller than the sum of its proper divisors (38242863708).

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

21253543332 is a wasteful number, since it uses less digits than its factorization.

21253543332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138441 (or 138439 counting only the distinct ones).

The product of its digits is 64800, while the sum is 33.

The spelling of 21253543332 in words is "twenty-one billion, two hundred fifty-three million, five hundred forty-three thousand, three hundred thirty-two".