28397790 has 40 divisors (see below), whose sum is σ = 76360680. Its totient is φ = 7572528.

The previous prime is 28397779. The next prime is 28397797. The reversal of 28397790 is 9779382.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28397797) 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 19 ways as a sum of consecutive naturals, for example, 16720 + ... + 18339.

It is an arithmetic number, because the mean of its divisors is an integer number (1909017).

Almost surely, 2^28397790 is an apocalyptic number.

28397790 is an abundant number, since it is smaller than the sum of its proper divisors (47962890).

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

28397790 is a wasteful number, since it uses less digits than its factorization.

28397790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35078 (or 35069 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 28397790 is about 5328.9576842005. The cubic root of 28397790 is about 305.0901462462.

The spelling of 28397790 in words is "twenty-eight million, three hundred ninety-seven thousand, seven hundred ninety".