28307444 has 24 divisors (see below), whose sum is σ = 54219648. Its totient is φ = 12824640.

The previous prime is 28307441. The next prime is 28307449. The reversal of 28307444 is 44470382.

It is a super-2 number, since 2×28307444² = 1602622771626272, 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 28307444.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28307441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15272 + ... + 17024.

It is an arithmetic number, because the mean of its divisors is an integer number (2259152).

Almost surely, 2^28307444 is an apocalyptic number.

It is an amenable number.

28307444 is a deficient number, since it is larger than the sum of its proper divisors (25912204).

28307444 is a wasteful number, since it uses less digits than its factorization.

28307444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2135 (or 2133 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 32.

The square root of 28307444 is about 5320.4740390307. The cubic root of 28307444 is about 304.7662600460.

The spelling of 28307444 in words is "twenty-eight million, three hundred seven thousand, four hundred forty-four".