15781641732481 has 16 divisors (see below), whose sum is σ = 15876910530000. Its totient is φ = 15686518284288.

The previous prime is 15781641732401. The next prime is 15781641732533. The reversal of 15781641732481 is 18423714618751.

It can be written as a sum of positive squares in 8 ways, for example, as 612494064400 + 15169147668081 = 782620^2 + 3894759^2 .

It is a cyclic number.

It is not a de Polignac number, because 15781641732481 - 2³³ = 15773051797889 is a prime.

It is a super-2 number, since 2×15781641732481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15781641732401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1586249095 + ... + 1586259043.

It is an arithmetic number, because the mean of its divisors is an integer number (992306908125).

Almost surely, 2^{15781641732481} is an apocalyptic number.

It is an amenable number.

15781641732481 is a deficient number, since it is larger than the sum of its proper divisors (95268797519).

15781641732481 is a wasteful number, since it uses less digits than its factorization.

15781641732481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16308.

The product of its digits is 9031680, while the sum is 58.

The spelling of 15781641732481 in words is "fifteen trillion, seven hundred eighty-one billion, six hundred forty-one million, seven hundred thirty-two thousand, four hundred eighty-one".