16563836561 has 8 divisors (see below), whose sum is σ = 17360149824. Its totient is φ = 15773868880.

The previous prime is 16563836557. The next prime is 16563836563.

16563836561 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16563836561 - 2² = 16563836557 is a prime.

It is a super-3 number, since 3×16563836561³ (a number of 32 digits) contains 333 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16563836563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1581050 + ... + 1591491.

It is an arithmetic number, because the mean of its divisors is an integer number (2170018728).

Almost surely, 2^16563836561 is an apocalyptic number.

It is an amenable number.

16563836561 is a deficient number, since it is larger than the sum of its proper divisors (796313263).

16563836561 is a wasteful number, since it uses less digits than its factorization.

16563836561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3172791.

The product of its digits is 2332800, while the sum is 50.

The spelling of 16563836561 in words is "sixteen billion, five hundred sixty-three million, eight hundred thirty-six thousand, five hundred sixty-one".