16636413561 has 4 divisors (see below), whose sum is σ = 22181884752. Its totient is φ = 11090942372.

The previous prime is 16636413539. The next prime is 16636413589. The reversal of 16636413561 is 16531463661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16636413561 - 2¹³ = 16636405369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16636413161) 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, 2772735591 + ... + 2772735596.

It is an arithmetic number, because the mean of its divisors is an integer number (5545471188).

Almost surely, 2^16636413561 is an apocalyptic number.

It is an amenable number.

16636413561 is a deficient number, since it is larger than the sum of its proper divisors (5545471191).

16636413561 is an equidigital number, since it uses as much as digits as its factorization.

16636413561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5545471190.

The product of its digits is 233280, while the sum is 42.

The spelling of 16636413561 in words is "sixteen billion, six hundred thirty-six million, four hundred thirteen thousand, five hundred sixty-one".