28715242 has 4 divisors (see below), whose sum is σ = 43072866. Its totient is φ = 14357620.

The previous prime is 28715233. The next prime is 28715257. The reversal of 28715242 is 24251782.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24251782 = 2 ⋅12125891.

It can be written as a sum of positive squares in only one way, i.e., 27888961 + 826281 = 5281^2 + 909^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7178809 + ... + 7178812.

Almost surely, 2^28715242 is an apocalyptic number.

28715242 is a deficient number, since it is larger than the sum of its proper divisors (14357624).

28715242 is a wasteful number, since it uses less digits than its factorization.

28715242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14357623.

The product of its digits is 8960, while the sum is 31.

The square root of 28715242 is about 5358.6604669451. The cubic root of 28715242 is about 306.2227790883. Note that the first 3 decimals are identical.

The spelling of 28715242 in words is "twenty-eight million, seven hundred fifteen thousand, two hundred forty-two".