28508738 has 4 divisors (see below), whose sum is σ = 42763110. Its totient is φ = 14254368.

The previous prime is 28508731. The next prime is 28508771. The reversal of 28508738 is 83780582.

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., 22686169 + 5822569 = 4763^2 + 2413^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28508695 and 28508704.

It is not an unprimeable number, because it can be changed into a prime (28508731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7127183 + ... + 7127186.

Almost surely, 2^28508738 is an apocalyptic number.

28508738 is a deficient number, since it is larger than the sum of its proper divisors (14254372).

28508738 is a wasteful number, since it uses less digits than its factorization.

28508738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14254371.

The product of its (nonzero) digits is 107520, while the sum is 41.

The square root of 28508738 is about 5339.3574519787. The cubic root of 28508738 is about 305.4869512437.

The spelling of 28508738 in words is "twenty-eight million, five hundred eight thousand, seven hundred thirty-eight".