28404438 has 8 divisors (see below), whose sum is σ = 56808888. Its totient is φ = 9468144.

The previous prime is 28404407. The next prime is 28404451. The reversal of 28404438 is 83440482.

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

28404438 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28404399 and 28404408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2367031 + ... + 2367042.

It is an arithmetic number, because the mean of its divisors is an integer number (7101111).

Almost surely, 2^28404438 is an apocalyptic number.

28404438 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28404438 is a wasteful number, since it uses less digits than its factorization.

28404438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4734078.

The product of its (nonzero) digits is 24576, while the sum is 33.

The square root of 28404438 is about 5329.5814094542. The cubic root of 28404438 is about 305.1139518668.

The spelling of 28404438 in words is "twenty-eight million, four hundred four thousand, four hundred thirty-eight".