21750241536 has 216 divisors, whose sum is σ = 64627833816. Its totient is φ = 7030702080.

The previous prime is 21750241511. The next prime is 21750241537. The reversal of 21750241536 is 63514205712.

It can be written as a sum of positive squares in 4 ways, for example, as 6969600 + 21743271936 = 2640^2 + 147456^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21750241536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21750241537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18230956 + ... + 18232148.

Almost surely, 2^21750241536 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 21750241536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32313916908).

21750241536 is an abundant number, since it is smaller than the sum of its proper divisors (42877592280).

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

21750241536 is a wasteful number, since it uses less digits than its factorization.

21750241536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1449 (or 1432 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The spelling of 21750241536 in words is "twenty-one billion, seven hundred fifty million, two hundred forty-one thousand, five hundred thirty-six".