28440445 has 24 divisors (see below), whose sum is σ = 38830680. Its totient is φ = 19958400.

The previous prime is 28440427. The next prime is 28440449. The reversal of 28440445 is 54404482.

It can be written as a sum of positive squares in 4 ways, for example, as 5963364 + 22477081 = 2442^2 + 4741^2 .

It is not a de Polignac number, because 28440445 - 2⁵ = 28440413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28440449) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16735 + ... + 18355.

It is an arithmetic number, because the mean of its divisors is an integer number (1617945).

Almost surely, 2^28440445 is an apocalyptic number.

It is an amenable number.

28440445 is a deficient number, since it is larger than the sum of its proper divisors (10390235).

28440445 is a wasteful number, since it uses less digits than its factorization.

28440445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1677 (or 1666 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 31.

The square root of 28440445 is about 5332.9583722358. The cubic root of 28440445 is about 305.2428237363.

The spelling of 28440445 in words is "twenty-eight million, four hundred forty thousand, four hundred forty-five".