19919799 has 6 divisors (see below), whose sum is σ = 28773056. Its totient is φ = 13279860.

The previous prime is 19919797. The next prime is 19919803. The reversal of 19919799 is 99791991.

It is not a de Polignac number, because 19919799 - 2¹ = 19919797 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 (19919791) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1106647 + ... + 1106664.

Almost surely, 2^19919799 is an apocalyptic number.

19919799 is a deficient number, since it is larger than the sum of its proper divisors (8853257).

19919799 is a wasteful number, since it uses less digits than its factorization.

19919799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2213317 (or 2213314 counting only the distinct ones).

The product of its digits is 413343, while the sum is 54.

The square root of 19919799 is about 4463.1602032641. The cubic root of 19919799 is about 271.0784439063.

The spelling of 19919799 in words is "nineteen million, nine hundred nineteen thousand, seven hundred ninety-nine".