19999999999 has 16 divisors (see below), whose sum is σ = 23212587328. Its totient is φ = 16878108672.

The previous prime is 19999999967. The next prime is 20000000089. The reversal of 19999999999 is 99999999991.

It is a cyclic number.

It is not a de Polignac number, because 19999999999 - 2⁵ = 19999999967 is a prime.

It is a super-9 number, since 9×19999999999⁹ (a number of 94 digits) contains 999999999 as substring.

It is a fibodiv number, since the Fibonacci-like sequence with seeds 1 and 9999999999 contains 19999999999 itself.

19999999999 is a modest number, since divided by 999999 gives 19999 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19999999939) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54739 + ... + 207355.

It is an arithmetic number, because the mean of its divisors is an integer number (1450786708).

Almost surely, 2^19999999999 is an apocalyptic number.

19999999999 is a deficient number, since it is larger than the sum of its proper divisors (3212587329).

19999999999 is a wasteful number, since it uses less digits than its factorization.

19999999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152914.

The product of its digits is 3486784401, while the sum is 91.

It can be divided in two parts, 19 and 999999999, that multiplied together give a palindrome (18999999981).

The spelling of 19999999999 in words is "nineteen billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".