28388434 has 8 divisors (see below), whose sum is σ = 42662988. Its totient is φ = 14167440.

The previous prime is 28388431. The next prime is 28388447. The reversal of 28388434 is 43488382.

It can be written as a sum of positive squares in 2 ways, for example, as 26574025 + 1814409 = 5155^2 + 1347^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (28388431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12037 + ... + 14200.

Almost surely, 2^28388434 is an apocalyptic number.

28388434 is a deficient number, since it is larger than the sum of its proper divisors (14274554).

28388434 is a wasteful number, since it uses less digits than its factorization.

28388434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26780.

The product of its digits is 147456, while the sum is 40.

The square root of 28388434 is about 5328.0797666702. The cubic root of 28388434 is about 305.0566373365.

The spelling of 28388434 in words is "twenty-eight million, three hundred eighty-eight thousand, four hundred thirty-four".