16561507201441 has 4 divisors (see below), whose sum is σ = 16562777950852. Its totient is φ = 16560236452032.

The previous prime is 16561507201433. The next prime is 16561507201471. The reversal of 16561507201441 is 14410270516561.

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 8763612915600 + 7797894285841 = 2960340^2 + 2792471^2 .

It is a cyclic number.

It is not a de Polignac number, because 16561507201441 - 2³ = 16561507201433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16561507201471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 635355156 + ... + 635381221.

It is an arithmetic number, because the mean of its divisors is an integer number (4140694487713).

Almost surely, 2^{16561507201441} is an apocalyptic number.

It is an amenable number.

16561507201441 is a deficient number, since it is larger than the sum of its proper divisors (1270749411).

16561507201441 is a wasteful number, since it uses less digits than its factorization.

16561507201441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270749410.

The product of its (nonzero) digits is 201600, while the sum is 43.

The spelling of 16561507201441 in words is "sixteen trillion, five hundred sixty-one billion, five hundred seven million, two hundred one thousand, four hundred forty-one".