19891812135 has 32 divisors (see below), whose sum is σ = 34614514368. Its totient is φ = 9695923200.

The previous prime is 19891812103. The next prime is 19891812137. The reversal of 19891812135 is 53121819891.

It is not a de Polignac number, because 19891812135 - 2⁵ = 19891812103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891812137) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 485302 + ... + 524691.

It is an arithmetic number, because the mean of its divisors is an integer number (1081703574).

Almost surely, 2^19891812135 is an apocalyptic number.

19891812135 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19891812135 is a deficient number, since it is larger than the sum of its proper divisors (14722702233).

19891812135 is a wasteful number, since it uses less digits than its factorization.

19891812135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010115.

The product of its digits is 155520, while the sum is 48.

The spelling of 19891812135 in words is "nineteen billion, eight hundred ninety-one million, eight hundred twelve thousand, one hundred thirty-five".