16127776865 has 4 divisors (see below), whose sum is σ = 19353332244. Its totient is φ = 12902221488.

The previous prime is 16127776813. The next prime is 16127776867. The reversal of 16127776865 is 56867772161.

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 2554594849 + 13573182016 = 50543^2 + 116504^2 .

It is a cyclic number.

It is not a de Polignac number, because 16127776865 - 2¹⁸ = 16127514721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16127776865.

It is not an unprimeable number, because it can be changed into a prime (16127776867) 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, 1612777682 + ... + 1612777691.

It is an arithmetic number, because the mean of its divisors is an integer number (4838333061).

Almost surely, 2^16127776865 is an apocalyptic number.

It is an amenable number.

16127776865 is a deficient number, since it is larger than the sum of its proper divisors (3225555379).

16127776865 is an equidigital number, since it uses as much as digits as its factorization.

16127776865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3225555378.

The product of its digits is 5927040, while the sum is 56.

The spelling of 16127776865 in words is "sixteen billion, one hundred twenty-seven million, seven hundred seventy-six thousand, eight hundred sixty-five".