28238642 has 4 divisors (see below), whose sum is σ = 42357966. Its totient is φ = 14119320.

The previous prime is 28238633. The next prime is 28238647. The reversal of 28238642 is 24683282.

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., 18309841 + 9928801 = 4279^2 + 3151^2 .

It is not an unprimeable number, because it can be changed into a prime (28238647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7059659 + ... + 7059662.

Almost surely, 2^28238642 is an apocalyptic number.

28238642 is a deficient number, since it is larger than the sum of its proper divisors (14119324).

28238642 is a wasteful number, since it uses less digits than its factorization.

28238642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14119323.

The product of its digits is 36864, while the sum is 35.

The square root of 28238642 is about 5314.0043281879. The cubic root of 28238642 is about 304.5191455486.

The spelling of 28238642 in words is "twenty-eight million, two hundred thirty-eight thousand, six hundred forty-two".