138305028 has 48 divisors (see below), whose sum is σ = 347621120. Its totient is φ = 42656544.

The previous prime is 138305017. The next prime is 138305029. The reversal of 138305028 is 820503831.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 138304986 and 138305004.

It is not an unprimeable number, because it can be changed into a prime (138305029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2751 + ... + 16857.

Almost surely, 2^138305028 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138305028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (173810560).

138305028 is an abundant number, since it is smaller than the sum of its proper divisors (209316092).

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

138305028 is a wasteful number, since it uses less digits than its factorization.

138305028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14176 (or 14174 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 138305028 is about 11760.3158120860. The cubic root of 138305028 is about 517.1453884649.

Adding to 138305028 its reverse (820503831), we get a palindrome (958808859).

The spelling of 138305028 in words is "one hundred thirty-eight million, three hundred five thousand, twenty-eight".