138218172 has 24 divisors (see below), whose sum is σ = 325643136. Its totient is φ = 45625008.

The previous prime is 138218167. The next prime is 138218183. The reversal of 138218172 is 271812831.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54678 + ... + 57149.

It is an arithmetic number, because the mean of its divisors is an integer number (13568464).

Almost surely, 2^138218172 is an apocalyptic number.

138218172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138218172 is an abundant number, since it is smaller than the sum of its proper divisors (187424964).

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

138218172 is a wasteful number, since it uses less digits than its factorization.

138218172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111937 (or 111935 counting only the distinct ones).

The product of its digits is 5376, while the sum is 33.

The square root of 138218172 is about 11756.6224741632. The cubic root of 138218172 is about 517.0371094758.

The spelling of 138218172 in words is "one hundred thirty-eight million, two hundred eighteen thousand, one hundred seventy-two".