21075471244944 has 400 divisors, whose sum is σ = 63406005260400. Its totient is φ = 6754629353472.

The previous prime is 21075471244907. The next prime is 21075471244969. The reversal of 21075471244944 is 44944217457012.

21075471244944 is a `hidden beast` number, since 2 + 1 + 0 + 7 + 547 + 1 + 2 + 4 + 4 + 94 + 4 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 9964502355600 + 11110968889344 = 3156660^2 + 3333312^2 .

It is a super-2 number, since 2×21075471244944² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 690779962 + ... + 690810470.

It is an arithmetic number, because the mean of its divisors is an integer number (158515013151).

Almost surely, 2^{21075471244944} is an apocalyptic number.

21075471244944 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 21075471244944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31703002630200).

21075471244944 is an abundant number, since it is smaller than the sum of its proper divisors (42330534015456).

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

21075471244944 is a wasteful number, since it uses less digits than its factorization.

21075471244944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30784 (or 30769 counting only the distinct ones).

The product of its (nonzero) digits is 9031680, while the sum is 54.

The spelling of 21075471244944 in words is "twenty-one trillion, seventy-five billion, four hundred seventy-one million, two hundred forty-four thousand, nine hundred forty-four".