28507238 has 4 divisors (see below), whose sum is σ = 42760860. Its totient is φ = 14253618.

The previous prime is 28507231. The next prime is 28507247. The reversal of 28507238 is 83270582.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 28507198 and 28507207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28507231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7126808 + ... + 7126811.

It is an arithmetic number, because the mean of its divisors is an integer number (10690215).

Almost surely, 2^28507238 is an apocalyptic number.

28507238 is a deficient number, since it is larger than the sum of its proper divisors (14253622).

28507238 is a wasteful number, since it uses less digits than its factorization.

28507238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14253621.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 28507238 is about 5339.2169837908. The cubic root of 28507238 is about 305.4815933723.

The spelling of 28507238 in words is "twenty-eight million, five hundred seven thousand, two hundred thirty-eight".