21546625728 has 112 divisors (see below), whose sum is σ = 57727169280. Its totient is φ = 7092096000.

The previous prime is 21546625721. The next prime is 21546625739. The reversal of 21546625728 is 82752664512.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (21546625721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8511823 + ... + 8514353.

Almost surely, 2^21546625728 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 21546625728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28863584640).

21546625728 is an abundant number, since it is smaller than the sum of its proper divisors (36180543552).

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

21546625728 is a wasteful number, since it uses less digits than its factorization.

21546625728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3086 (or 3076 counting only the distinct ones).

The product of its digits is 1612800, while the sum is 48.

The spelling of 21546625728 in words is "twenty-one billion, five hundred forty-six million, six hundred twenty-five thousand, seven hundred twenty-eight".