19985309895 has 16 divisors (see below), whose sum is σ = 31982503392. Its totient is φ = 10656829440.

The previous prime is 19985309887. The next prime is 19985309899. The reversal of 19985309895 is 59890358991.

It is not a de Polignac number, because 19985309895 - 2³ = 19985309887 is a prime.

It is a super-2 number, since 2×19985309895² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19985309899) 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, 40822 + ... + 204051.

It is an arithmetic number, because the mean of its divisors is an integer number (1998906462).

Almost surely, 2^19985309895 is an apocalyptic number.

19985309895 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19985309895 is a deficient number, since it is larger than the sum of its proper divisors (11997193497).

19985309895 is a wasteful number, since it uses less digits than its factorization.

19985309895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250322.

The product of its (nonzero) digits is 31492800, while the sum is 66.

The spelling of 19985309895 in words is "nineteen billion, nine hundred eighty-five million, three hundred nine thousand, eight hundred ninety-five".