28508440 has 16 divisors (see below), whose sum is σ = 64144080. Its totient is φ = 11403360.

The previous prime is 28508429. The next prime is 28508449. The reversal of 28508440 is 4480582.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28508449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356316 + ... + 356395.

It is an arithmetic number, because the mean of its divisors is an integer number (4009005).

Almost surely, 2^28508440 is an apocalyptic number.

28508440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28508440 is an abundant number, since it is smaller than the sum of its proper divisors (35635640).

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

28508440 is a wasteful number, since it uses less digits than its factorization.

28508440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712722 (or 712718 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 31.

The square root of 28508440 is about 5339.3295459262. The cubic root of 28508440 is about 305.4858868282.

The spelling of 28508440 in words is "twenty-eight million, five hundred eight thousand, four hundred forty".