16641133865 has 4 divisors (see below), whose sum is σ = 19969360644. Its totient is φ = 13312907088.

The previous prime is 16641133849. The next prime is 16641133871. The reversal of 16641133865 is 56833114661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56833114661 = 137 ⋅414840253.

It can be written as a sum of positive squares in 2 ways, for example, as 10239213721 + 6401920144 = 101189^2 + 80012^2 .

It is a cyclic number.

It is not a de Polignac number, because 16641133865 - 2⁴ = 16641133849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1664113382 + ... + 1664113391.

It is an arithmetic number, because the mean of its divisors is an integer number (4992340161).

Almost surely, 2^16641133865 is an apocalyptic number.

It is an amenable number.

16641133865 is a deficient number, since it is larger than the sum of its proper divisors (3328226779).

16641133865 is an equidigital number, since it uses as much as digits as its factorization.

16641133865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3328226778.

The product of its digits is 311040, while the sum is 44.

The spelling of 16641133865 in words is "sixteen billion, six hundred forty-one million, one hundred thirty-three thousand, eight hundred sixty-five".