28005144 has 32 divisors (see below), whose sum is σ = 70152000. Its totient is φ = 9316512.

The previous prime is 28005139. The next prime is 28005149. The reversal of 28005144 is 44150082.

It is an interprime number because it is at equal distance from previous prime (28005139) and next prime (28005149).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28005149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16947 + ... + 18525.

It is an arithmetic number, because the mean of its divisors is an integer number (2192250).

Almost surely, 2^28005144 is an apocalyptic number.

28005144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28005144 is an abundant number, since it is smaller than the sum of its proper divisors (42146856).

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

28005144 is a wasteful number, since it uses less digits than its factorization.

28005144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2327 (or 2323 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 28005144 is about 5291.9886621194. The cubic root of 28005144 is about 303.6774915414.

The spelling of 28005144 in words is "twenty-eight million, five thousand, one hundred forty-four".