21744218240 has 64 divisors (see below), whose sum is σ = 52079186520. Its totient is φ = 8681472000.

The previous prime is 21744218231. The next prime is 21744218281. The reversal of 21744218240 is 4281244712.

It can be written as a sum of positive squares in 4 ways, for example, as 11220741184 + 10523477056 = 105928^2 + 102584^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×21744218240² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21744218240.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 314840 + ... + 377640.

Almost surely, 2^21744218240 is an apocalyptic number.

21744218240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21744218240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26039593260).

21744218240 is an abundant number, since it is smaller than the sum of its proper divisors (30334968280).

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

21744218240 is an equidigital number, since it uses as much as digits as its factorization.

21744218240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63361 (or 63349 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 35.

The spelling of 21744218240 in words is "twenty-one billion, seven hundred forty-four million, two hundred eighteen thousand, two hundred forty".