15981538761473 has 4 divisors (see below), whose sum is σ = 15981757397508. Its totient is φ = 15981320125440.

The previous prime is 15981538761469. The next prime is 15981538761497. The reversal of 15981538761473 is 37416783518951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2394146573809 + 13587392187664 = 1547303^2 + 3686108^2 .

It is a cyclic number.

It is not a de Polignac number, because 15981538761473 - 2² = 15981538761469 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15981538761373) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 109208336 + ... + 109354577.

It is an arithmetic number, because the mean of its divisors is an integer number (3995439349377).

Almost surely, 2^{15981538761473} is an apocalyptic number.

It is an amenable number.

15981538761473 is a deficient number, since it is larger than the sum of its proper divisors (218636035).

15981538761473 is an equidigital number, since it uses as much as digits as its factorization.

15981538761473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218636034.

The product of its digits is 152409600, while the sum is 68.

The spelling of 15981538761473 in words is "fifteen trillion, nine hundred eighty-one billion, five hundred thirty-eight million, seven hundred sixty-one thousand, four hundred seventy-three".