28843640 has 64 divisors (see below), whose sum is σ = 76584960. Its totient is φ = 9567360.

The previous prime is 28843637. The next prime is 28843649. The reversal of 28843640 is 4634882.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 28843640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28843649) 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 15 ways as a sum of consecutive naturals, for example, 7019 + ... + 10341.

It is an arithmetic number, because the mean of its divisors is an integer number (1196640).

Almost surely, 2^28843640 is an apocalyptic number.

28843640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28843640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38292480).

28843640 is an abundant number, since it is smaller than the sum of its proper divisors (47741320).

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

28843640 is a wasteful number, since it uses less digits than its factorization.

28843640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3372 (or 3368 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 35.

The square root of 28843640 is about 5370.6275238560. The cubic root of 28843640 is about 306.6785177105.

The spelling of 28843640 in words is "twenty-eight million, eight hundred forty-three thousand, six hundred forty".