19966799 has 4 divisors (see below), whose sum is σ = 20046600. Its totient is φ = 19887000.

The previous prime is 19966769. The next prime is 19966801. The reversal of 19966799 is 99766991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19966799 - 2²⁴ = 3189583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19966769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39524 + ... + 40025.

It is an arithmetic number, because the mean of its divisors is an integer number (5011650).

Almost surely, 2^19966799 is an apocalyptic number.

19966799 is a deficient number, since it is larger than the sum of its proper divisors (79801).

19966799 is an equidigital number, since it uses as much as digits as its factorization.

19966799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79800.

The product of its digits is 1653372, while the sum is 56.

The square root of 19966799 is about 4468.4224285535. The cubic root of 19966799 is about 271.2914761695.

The spelling of 19966799 in words is "nineteen million, nine hundred sixty-six thousand, seven hundred ninety-nine".