21124545312 has 96 divisors (see below), whose sum is σ = 60265719360. Its totient is φ = 6440186880.

The previous prime is 21124545311. The next prime is 21124545329. The reversal of 21124545312 is 21354542112.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 21124545312.

It is not an unprimeable number, because it can be changed into a prime (21124545311) 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 15 ways as a sum of consecutive naturals, for example, 58387 + ... + 213677.

It is an arithmetic number, because the mean of its divisors is an integer number (627767910).

Almost surely, 2^21124545312 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 21124545312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30132859680).

21124545312 is an abundant number, since it is smaller than the sum of its proper divisors (39141174048).

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

21124545312 is a wasteful number, since it uses less digits than its factorization.

21124545312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155426 (or 155418 counting only the distinct ones).

The product of its digits is 9600, while the sum is 30.

The spelling of 21124545312 in words is "twenty-one billion, one hundred twenty-four million, five hundred forty-five thousand, three hundred twelve".