28400508 has 18 divisors (see below), whose sum is σ = 71790264. Its totient is φ = 9466824.

The previous prime is 28400507. The next prime is 28400513. The reversal of 28400508 is 80500482.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28400503) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 394416 + ... + 394487.

It is an arithmetic number, because the mean of its divisors is an integer number (3988348).

Almost surely, 2^28400508 is an apocalyptic number.

It is an amenable number.

28400508 is an abundant number, since it is smaller than the sum of its proper divisors (43389756).

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

28400508 is a wasteful number, since it uses less digits than its factorization.

28400508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788913 (or 788908 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 28400508 is about 5329.2126998272. The cubic root of 28400508 is about 305.0998794985.

The spelling of 28400508 in words is "twenty-eight million, four hundred thousand, five hundred eight".