16561506555115 has 16 divisors (see below), whose sum is σ = 20594135731680. Its totient is φ = 12770543296000.

The previous prime is 16561506555073. The next prime is 16561506555137. The reversal of 16561506555115 is 51155560516561.

It is a happy number.

It is not a de Polignac number, because 16561506555115 - 2¹⁵ = 16561506522347 is a prime.

It is a super-2 number, since 2×16561506555115² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97203886 + ... + 97374115.

It is an arithmetic number, because the mean of its divisors is an integer number (1287133483230).

Almost surely, 2^{16561506555115} is an apocalyptic number.

16561506555115 is a deficient number, since it is larger than the sum of its proper divisors (4032629176565).

16561506555115 is a wasteful number, since it uses less digits than its factorization.

16561506555115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194578622.

The product of its (nonzero) digits is 3375000, while the sum is 52.

The spelling of 16561506555115 in words is "sixteen trillion, five hundred sixty-one billion, five hundred six million, five hundred fifty-five thousand, one hundred fifteen".