21291702404544 has 1344 divisors, whose sum is σ = 76046370656256. Its totient is φ = 5607014400000.

The previous prime is 21291702404507. The next prime is 21291702404561. The reversal of 21291702404544 is 44540420719212.

21291702404544 is a `hidden beast` number, since 2 + 1 + 2 + 9 + 170 + 24 + 0 + 454 + 4 = 666.

21291702404544 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21291702404544.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 17728311144 + ... + 17728312344.

It is an arithmetic number, because the mean of its divisors is an integer number (56582121024).

Almost surely, 2^{21291702404544} is an apocalyptic number.

21291702404544 is a gapful number since it is divisible by the number (24) 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 21291702404544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38023185328128).

21291702404544 is an abundant number, since it is smaller than the sum of its proper divisors (54754668251712).

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

21291702404544 is a wasteful number, since it uses less digits than its factorization.

21291702404544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1458 (or 1445 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 21291702404544 in words is "twenty-one trillion, two hundred ninety-one billion, seven hundred two million, four hundred four thousand, five hundred forty-four".