16545592561 has 4 divisors (see below), whose sum is σ = 16589951092. Its totient is φ = 16501234032.

The previous prime is 16545592541. The next prime is 16545592577. The reversal of 16545592561 is 16529554561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16529554561 = 13 ⋅1271504197.

It can be written as a sum of positive squares in 2 ways, for example, as 14156240400 + 2389352161 = 118980^2 + 48881^2 .

It is a cyclic number.

It is not a de Polignac number, because 16545592561 - 2⁵ = 16545592529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16545592541) 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 3 ways as a sum of consecutive naturals, for example, 22178706 + ... + 22179451.

It is an arithmetic number, because the mean of its divisors is an integer number (4147487773).

Almost surely, 2^16545592561 is an apocalyptic number.

It is an amenable number.

16545592561 is a deficient number, since it is larger than the sum of its proper divisors (44358531).

16545592561 is an equidigital number, since it uses as much as digits as its factorization.

16545592561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44358530.

The product of its digits is 1620000, while the sum is 49.

The spelling of 16545592561 in words is "sixteen billion, five hundred forty-five million, five hundred ninety-two thousand, five hundred sixty-one".