16564694819 has 4 divisors (see below), whose sum is σ = 16568271744. Its totient is φ = 16561117896.

The previous prime is 16564694803. The next prime is 16564694833. The reversal of 16564694819 is 91849646561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91849646561 = 4253 ⋅21596437.

It is a cyclic number.

It is not a de Polignac number, because 16564694819 - 2⁴ = 16564694803 is a prime.

It is a super-2 number, since 2×16564694819² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16564694869) 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, 1781507 + ... + 1790780.

It is an arithmetic number, because the mean of its divisors is an integer number (4142067936).

Almost surely, 2^16564694819 is an apocalyptic number.

16564694819 is a deficient number, since it is larger than the sum of its proper divisors (3576925).

16564694819 is an equidigital number, since it uses as much as digits as its factorization.

16564694819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3576924.

The product of its digits is 11197440, while the sum is 59.

The spelling of 16564694819 in words is "sixteen billion, five hundred sixty-four million, six hundred ninety-four thousand, eight hundred nineteen".