19999599999 has 4 divisors (see below), whose sum is σ = 26666133336. Its totient is φ = 13333066664.

The previous prime is 19999599967. The next prime is 19999600007. The reversal of 19999599999 is 99999599991.

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 19999599999 - 2⁵ = 19999599967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19999595999) 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, 3333266664 + ... + 3333266669.

It is an arithmetic number, because the mean of its divisors is an integer number (6666533334).

Almost surely, 2^19999599999 is an apocalyptic number.

19999599999 is a deficient number, since it is larger than the sum of its proper divisors (6666533337).

19999599999 is an equidigital number, since it uses as much as digits as its factorization.

19999599999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6666533336.

The product of its digits is 1937102445, while the sum is 87.

The spelling of 19999599999 in words is "nineteen billion, nine hundred ninety-nine million, five hundred ninety-nine thousand, nine hundred ninety-nine".