16561384587 has 18 divisors (see below), whose sum is σ = 26294431436. Its totient is φ = 10037202120.

The previous prime is 16561384571. The next prime is 16561384601. The reversal of 16561384587 is 78548316561.

It is a happy number.

16561384587 is a `hidden beast` number, since 1 + 6 + 56 + 1 + 3 + 8 + 4 + 587 = 666.

It is not a de Polignac number, because 16561384587 - 2⁴ = 16561384571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16561384517) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7602853 + ... + 7605030.

Almost surely, 2^16561384587 is an apocalyptic number.

16561384587 is a deficient number, since it is larger than the sum of its proper divisors (9733046849).

16561384587 is a wasteful number, since it uses less digits than its factorization.

16561384587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15207911 (or 15207897 counting only the distinct ones).

The product of its digits is 4838400, while the sum is 54.

The spelling of 16561384587 in words is "sixteen billion, five hundred sixty-one million, three hundred eighty-four thousand, five hundred eighty-seven".