18435542172 has 24 divisors (see below), whose sum is σ = 43088821776. Its totient is φ = 6134815488.

The previous prime is 18435542171. The next prime is 18435542197. The reversal of 18435542172 is 27124553481.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18435542171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1288243 + ... + 1302474.

It is an arithmetic number, because the mean of its divisors is an integer number (1795367574).

Almost surely, 2^18435542172 is an apocalyptic number.

18435542172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18435542172 is an abundant number, since it is smaller than the sum of its proper divisors (24653279604).

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

18435542172 is a wasteful number, since it uses less digits than its factorization.

18435542172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591317 (or 2591315 counting only the distinct ones).

The product of its digits is 268800, while the sum is 42.

The spelling of 18435542172 in words is "eighteen billion, four hundred thirty-five million, five hundred forty-two thousand, one hundred seventy-two".