21576136480144 has 135 divisors (see below), whose sum is σ = 45003617190273. Its totient is φ = 10018956443136.

The previous prime is 21576136480111. The next prime is 21576136480163. The reversal of 21576136480144 is 44108463167512.

The square root of 21576136480144 is 4645012.

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., 16798030131600 + 4778106348544 = 4098540^2 + 2185888^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21576136480091 and 21576136480100.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 26216447317 + ... + 26216448139.

Almost surely, 2^{21576136480144} is an apocalyptic number.

21576136480144 is the 4645012-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21576136480144

21576136480144 is an abundant number, since it is smaller than the sum of its proper divisors (23427480710129).

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

21576136480144 is an frugal number, since it uses more digits than its factorization.

21576136480144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854 (or 925 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 52.

The spelling of 21576136480144 in words is "twenty-one trillion, five hundred seventy-six billion, one hundred thirty-six million, four hundred eighty thousand, one hundred forty-four".