28269440 has 32 divisors (see below), whose sum is σ = 67583160. Its totient is φ = 11307520.

The previous prime is 28269401. The next prime is 28269491. The reversal of 28269440 is 4496282.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×28269440² = 1598322475827200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28269440.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 21446 + ... + 22725.

Almost surely, 2^28269440 is an apocalyptic number.

28269440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28269440 is an abundant number, since it is smaller than the sum of its proper divisors (39313720).

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

28269440 is an equidigital number, since it uses as much as digits as its factorization.

28269440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44190 (or 44178 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 28269440 is about 5316.9013532320. The cubic root of 28269440 is about 304.6298115546.

The spelling of 28269440 in words is "twenty-eight million, two hundred sixty-nine thousand, four hundred forty".