21940005888256 has 81 divisors (see below), whose sum is σ = 44083267625901. Its totient is φ = 10898093930496.

The previous prime is 21940005888253. The next prime is 21940005888341. The reversal of 21940005888256 is 65288850004912.

The square root of 21940005888256 is 4684016.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 621322297600 + 21318683590656 = 788240^2 + 4617216^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21940005888256.

It is not an unprimeable number, because it can be changed into a prime (21940005888253) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12515689876 + ... + 12515691628.

Almost surely, 2^{21940005888256} is an apocalyptic number.

21940005888256 is the 4684016-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21940005888256

21940005888256 is an abundant number, since it is smaller than the sum of its proper divisors (22143261737645).

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

21940005888256 is an frugal number, since it uses more digits than its factorization.

21940005888256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3856 (or 1922 counting only the distinct ones).

The product of its (nonzero) digits is 11059200, while the sum is 58.

The spelling of 21940005888256 in words is "twenty-one trillion, nine hundred forty billion, five million, eight hundred eighty-eight thousand, two hundred fifty-six".