19999699 has 4 divisors (see below), whose sum is σ = 20100400. Its totient is φ = 19899000.

The previous prime is 19999697. The next prime is 19999729. The reversal of 19999699 is 99699991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99699991 = 877 ⋅113683.

It is a cyclic number.

It is not a de Polignac number, because 19999699 - 2¹ = 19999697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19999697) 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, 50052 + ... + 50449.

It is an arithmetic number, because the mean of its divisors is an integer number (5025100).

Almost surely, 2^19999699 is an apocalyptic number.

19999699 is a deficient number, since it is larger than the sum of its proper divisors (100701).

19999699 is a wasteful number, since it uses less digits than its factorization.

19999699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100700.

The product of its digits is 3188646, while the sum is 61.

The square root of 19999699 is about 4472.1023020499. The cubic root of 19999699 is about 271.4403999198.

The spelling of 19999699 in words is "nineteen million, nine hundred ninety-nine thousand, six hundred ninety-nine".