21530543342250 has 128 divisors (see below), whose sum is σ = 54109060042752. Its totient is φ = 5702092200000.

The previous prime is 21530543342219. The next prime is 21530543342251. The reversal of 21530543342250 is 5224334503512.

It is a super-2 number, since 2×21530543342250² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21530543342199 and 21530543342208.

It is not an unprimeable number, because it can be changed into a prime (21530543342251) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 528064365 + ... + 528105135.

It is an arithmetic number, because the mean of its divisors is an integer number (422727031584).

Almost surely, 2^{21530543342250} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21530543342250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27054530021376).

21530543342250 is an abundant number, since it is smaller than the sum of its proper divisors (32578516700502).

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

21530543342250 is a wasteful number, since it uses less digits than its factorization.

21530543342250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45605 (or 45595 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 39.

Adding to 21530543342250 its reverse (5224334503512), we get a palindrome (26754877845762).

The spelling of 21530543342250 in words is "twenty-one trillion, five hundred thirty billion, five hundred forty-three million, three hundred forty-two thousand, two hundred fifty".