138289728 has 56 divisors (see below), whose sum is σ = 366784128. Its totient is φ = 45984256.

The previous prime is 138289727. The next prime is 138289783. The reversal of 138289728 is 827982831.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (138289727) 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, 124825 + ... + 125927.

Almost surely, 2^138289728 is an apocalyptic number.

It is an amenable number.

138289728 is an abundant number, since it is smaller than the sum of its proper divisors (228494400).

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

138289728 is a wasteful number, since it uses less digits than its factorization.

138289728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1771 (or 1761 counting only the distinct ones).

The product of its digits is 387072, while the sum is 48.

The square root of 138289728 is about 11759.6653013596. The cubic root of 138289728 is about 517.1263180176.

The spelling of 138289728 in words is "one hundred thirty-eight million, two hundred eighty-nine thousand, seven hundred twenty-eight".