28135138 has 4 divisors (see below), whose sum is σ = 42202710. Its totient is φ = 14067568.

The previous prime is 28135111. The next prime is 28135147. The reversal of 28135138 is 83153182.

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., 16459249 + 11675889 = 4057^2 + 3417^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7033783 + ... + 7033786.

Almost surely, 2^28135138 is an apocalyptic number.

28135138 is a deficient number, since it is larger than the sum of its proper divisors (14067572).

28135138 is a wasteful number, since it uses less digits than its factorization.

28135138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14067571.

The product of its digits is 5760, while the sum is 31.

The square root of 28135138 is about 5304.2565925868. The cubic root of 28135138 is about 304.1466354566.

The spelling of 28135138 in words is "twenty-eight million, one hundred thirty-five thousand, one hundred thirty-eight".