28144387 has 12 divisors (see below), whose sum is σ = 29822184. Its totient is φ = 26554880.

The previous prime is 28144331. The next prime is 28144393. The reversal of 28144387 is 78344182.

It is not a de Polignac number, because 28144387 - 2²³ = 19755779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28144687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43587 + ... + 44227.

It is an arithmetic number, because the mean of its divisors is an integer number (2485182).

Almost surely, 2^28144387 is an apocalyptic number.

28144387 is a deficient number, since it is larger than the sum of its proper divisors (1677797).

28144387 is an equidigital number, since it uses as much as digits as its factorization.

28144387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 747 counting only the distinct ones).

The product of its digits is 43008, while the sum is 37.

The square root of 28144387 is about 5305.1283679097. The cubic root of 28144387 is about 304.1799596701.

The spelling of 28144387 in words is "twenty-eight million, one hundred forty-four thousand, three hundred eighty-seven".