28178242 has 4 divisors (see below), whose sum is σ = 42267366. Its totient is φ = 14089120.

The previous prime is 28178237. The next prime is 28178263. The reversal of 28178242 is 24287182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24287182 = 2 ⋅12143591.

It can be written as a sum of positive squares in only one way, i.e., 20061441 + 8116801 = 4479^2 + 2849^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28178198 and 28178207.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7044559 + ... + 7044562.

Almost surely, 2^28178242 is an apocalyptic number.

28178242 is a deficient number, since it is larger than the sum of its proper divisors (14089124).

28178242 is a wasteful number, since it uses less digits than its factorization.

28178242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14089123.

The product of its digits is 14336, while the sum is 34.

The square root of 28178242 is about 5308.3181894080. The cubic root of 28178242 is about 304.3018772437.

The spelling of 28178242 in words is "twenty-eight million, one hundred seventy-eight thousand, two hundred forty-two".