28428288 has 96 divisors (see below), whose sum is σ = 86748480. Its totient is φ = 8110080.

The previous prime is 28428287. The next prime is 28428307. The reversal of 28428288 is 88282482.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×28428288² = 1616335117221888, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (28428287) 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, 42678 + ... + 43338.

It is an arithmetic number, because the mean of its divisors is an integer number (903630).

Almost surely, 2^28428288 is an apocalyptic number.

28428288 is a gapful number since it is divisible by the number (28) 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 28428288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43374240).

28428288 is an abundant number, since it is smaller than the sum of its proper divisors (58320192).

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

28428288 is an equidigital number, since it uses as much as digits as its factorization.

28428288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 673 counting only the distinct ones).

The product of its digits is 131072, while the sum is 42.

The square root of 28428288 is about 5331.8184515229. The cubic root of 28428288 is about 305.1993250513.

The spelling of 28428288 in words is "twenty-eight million, four hundred twenty-eight thousand, two hundred eighty-eight".