28815138 has 24 divisors (see below), whose sum is σ = 68108976. Its totient is φ = 8731800.

The previous prime is 28815133. The next prime is 28815139. The reversal of 28815138 is 83151882.

It is not an unprimeable number, because it can be changed into a prime (28815133) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72568 + ... + 72963.

It is an arithmetic number, because the mean of its divisors is an integer number (2837874).

Almost surely, 2^28815138 is an apocalyptic number.

28815138 is an abundant number, since it is smaller than the sum of its proper divisors (39293838).

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

28815138 is a wasteful number, since it uses less digits than its factorization.

28815138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145550 (or 145547 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 28815138 is about 5367.9733605896. The cubic root of 28815138 is about 306.5774690699.

It can be divided in two parts, 288 and 15138, that multiplied together give a square (4359744 = 2088²).

The spelling of 28815138 in words is "twenty-eight million, eight hundred fifteen thousand, one hundred thirty-eight".