16613236654561 has 4 divisors (see below), whose sum is σ = 16674995898900. Its totient is φ = 16551477410224.

The previous prime is 16613236654459. The next prime is 16613236654603. The reversal of 16613236654561 is 16545663231661.

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 10390107710161 + 6223128944400 = 3223369^2 + 2494620^2 .

It is a cyclic number.

It is not a de Polignac number, because 16613236654561 - 2²⁵ = 16613203100129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16613236654961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30879621766 + ... + 30879622303.

It is an arithmetic number, because the mean of its divisors is an integer number (4168748974725).

Almost surely, 2^{16613236654561} is an apocalyptic number.

It is an amenable number.

16613236654561 is a deficient number, since it is larger than the sum of its proper divisors (61759244339).

16613236654561 is an equidigital number, since it uses as much as digits as its factorization.

16613236654561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61759244338.

The product of its digits is 13996800, while the sum is 55.

The spelling of 16613236654561 in words is "sixteen trillion, six hundred thirteen billion, two hundred thirty-six million, six hundred fifty-four thousand, five hundred sixty-one".