28731442 has 4 divisors (see below), whose sum is σ = 43097166. Its totient is φ = 14365720.

The previous prime is 28731433. The next prime is 28731449. The reversal of 28731442 is 24413782.

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., 17715681 + 11015761 = 4209^2 + 3319^2 .

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 not an unprimeable number, because it can be changed into a prime (28731449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7182859 + ... + 7182862.

Almost surely, 2^28731442 is an apocalyptic number.

28731442 is a deficient number, since it is larger than the sum of its proper divisors (14365724).

28731442 is a wasteful number, since it uses less digits than its factorization.

28731442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14365723.

The product of its digits is 10752, while the sum is 31.

The square root of 28731442 is about 5360.1718256041. The cubic root of 28731442 is about 306.2803545090.

The spelling of 28731442 in words is "twenty-eight million, seven hundred thirty-one thousand, four hundred forty-two".