12891123432 has 160 divisors (see below), whose sum is σ = 40133918880. Its totient is φ = 3832583040.

The previous prime is 12891123431. The next prime is 12891123433. The reversal of 12891123432 is 23432119821.

12891123432 is a `hidden beast` number, since 12 + 8 + 91 + 123 + 432 = 666.

12891123432 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (12891123431) and next prime (12891123433).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (12891123431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 360723 + ... + 394845.

It is an arithmetic number, because the mean of its divisors is an integer number (250836993).

Almost surely, 2^12891123432 is an apocalyptic number.

12891123432 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12891123432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20066959440).

12891123432 is an abundant number, since it is smaller than the sum of its proper divisors (27242795448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12891123432 is a wasteful number, since it uses less digits than its factorization.

12891123432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34205 (or 34192 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The spelling of 12891123432 in words is "twelve billion, eight hundred ninety-one million, one hundred twenty-three thousand, four hundred thirty-two".