28869138 has 24 divisors (see below), whose sum is σ = 62902476. Its totient is φ = 9568800.

The previous prime is 28869121. The next prime is 28869157. The reversal of 28869138 is 83196882.

It can be written as a sum of positive squares in 2 ways, for example, as 28869129 + 9 = 5373^2 + 3^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28869093 and 28869102.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1173 + ... + 7688.

Almost surely, 2^28869138 is an apocalyptic number.

28869138 is an abundant number, since it is smaller than the sum of its proper divisors (34033338).

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

28869138 is a wasteful number, since it uses less digits than its factorization.

28869138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9050 (or 9047 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 28869138 is about 5373.0008375209. Note that the first 3 decimals coincide. The cubic root of 28869138 is about 306.7688598189.

The spelling of 28869138 in words is "twenty-eight million, eight hundred sixty-nine thousand, one hundred thirty-eight".