138786228 has 108 divisors (see below), whose sum is σ = 422325540. Its totient is φ = 38271744.

The previous prime is 138786191. The next prime is 138786233. The reversal of 138786228 is 822687831.

138786228 is a `hidden beast` number, since 13 + 8 + 7 + 8 + 622 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 113806224 + 24980004 = 10668^2 + 4998^2 .

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 35 ways as a sum of consecutive naturals, for example, 49800 + ... + 52512.

Almost surely, 2^138786228 is an apocalyptic number.

138786228 is a gapful number since it is divisible by the number (18) 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 138786228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211162770).

138786228 is an abundant number, since it is smaller than the sum of its proper divisors (283539312).

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

138786228 is a wasteful number, since it uses less digits than its factorization.

138786228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2766 (or 2754 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 138786228 is about 11780.7566819793. The cubic root of 138786228 is about 517.7444563743.

The spelling of 138786228 in words is "one hundred thirty-eight million, seven hundred eighty-six thousand, two hundred twenty-eight".