28339138 has 4 divisors (see below), whose sum is σ = 42508710. Its totient is φ = 14169568.

The previous prime is 28339123. The next prime is 28339139. The reversal of 28339138 is 83193382.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18809569 + 9529569 = 4337^2 + 3087^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28339097 and 28339106.

It is not an unprimeable number, because it can be changed into a prime (28339139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7084783 + ... + 7084786.

Almost surely, 2^28339138 is an apocalyptic number.

28339138 is a deficient number, since it is larger than the sum of its proper divisors (14169572).

28339138 is a wasteful number, since it uses less digits than its factorization.

28339138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14169571.

The product of its digits is 31104, while the sum is 37.

The square root of 28339138 is about 5323.4516997903. The cubic root of 28339138 is about 304.8799599281.

The spelling of 28339138 in words is "twenty-eight million, three hundred thirty-nine thousand, one hundred thirty-eight".