16504645633281 has 75 divisors (see below), whose sum is σ = 26719610241093. Its totient is φ = 10152902419920.

The previous prime is 16504645633271. The next prime is 16504645633283. The reversal of 16504645633281 is 18233654640561.

The square root of 16504645633281 is 4062591.

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

16504645633281 is a `hidden beast` number, since 1 + 6 + 5 + 0 + 46 + 4 + 563 + 32 + 8 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8183266930881 + 8321378702400 = 2860641^2 + 2884680^2 .

It is not a de Polignac number, because 16504645633281 - 2¹³ = 16504645625089 is a prime.

It is a super-2 number, since 2×16504645633281² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16504645633283) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 6179199576 + ... + 6179202246.

Almost surely, 2^{16504645633281} is an apocalyptic number.

16504645633281 is the 4062591-st square number.

16504645633281 is the 2031296-th centered octagonal number.

It is an amenable number.

16504645633281 is a deficient number, since it is larger than the sum of its proper divisors (10214964607812).

16504645633281 is an frugal number, since it uses more digits than its factorization.

16504645633281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5406 (or 2687 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 54.

The spelling of 16504645633281 in words is "sixteen trillion, five hundred four billion, six hundred forty-five million, six hundred thirty-three thousand, two hundred eighty-one".