139028 has 6 divisors (see below), whose sum is σ = 243306. Its totient is φ = 69512.

The previous prime is 139021. The next prime is 139033. The reversal of 139028 is 820931.

It can be written as a sum of positive squares in only one way, i.e., 103684 + 35344 = 322^2 + 188^2 .

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 138994 and 139012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17375 + ... + 17382.

It is an arithmetic number, because the mean of its divisors is an integer number (40551).

2¹³⁹⁰²⁸ is an apocalyptic number.

It is an amenable number.

139028 is a deficient number, since it is larger than the sum of its proper divisors (104278).

139028 is a wasteful number, since it uses less digits than its factorization.

139028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34761 (or 34759 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 139028 is about 372.8645866799. The cubic root of 139028 is about 51.8044926859.

Adding to 139028 its reverse (820931), we get a palindrome (959959).

The spelling of 139028 in words is "one hundred thirty-nine thousand, twenty-eight".