18139506 has 96 divisors (see below), whose sum is σ = 47278080. Its totient is φ = 4586400.

The previous prime is 18139501. The next prime is 18139523. The reversal of 18139506 is 60593181.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18139501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 229575 + ... + 229653.

It is an arithmetic number, because the mean of its divisors is an integer number (492480).

Almost surely, 2^18139506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18139506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23639040).

18139506 is an abundant number, since it is smaller than the sum of its proper divisors (29138574).

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

18139506 is a wasteful number, since it uses less digits than its factorization.

18139506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 18139506 is about 4259.0498940491. The cubic root of 18139506 is about 262.7494517617.

The spelling of 18139506 in words is "eighteen million, one hundred thirty-nine thousand, five hundred six".