28665880 has 32 divisors (see below), whose sum is σ = 64981440. Its totient is φ = 11380480.

The previous prime is 28665869. The next prime is 28665881. The reversal of 28665880 is 8856682.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28665881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2865 + ... + 8095.

It is an arithmetic number, because the mean of its divisors is an integer number (2030670).

Almost surely, 2^28665880 is an apocalyptic number.

28665880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28665880 is an abundant number, since it is smaller than the sum of its proper divisors (36315560).

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

28665880 is a wasteful number, since it uses less digits than its factorization.

28665880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5379 (or 5375 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The square root of 28665880 is about 5354.0526706412. The cubic root of 28665880 is about 306.0472110221.

It can be divided in two parts, 286 and 65880, that added together give a palindrome (66166).

The spelling of 28665880 in words is "twenty-eight million, six hundred sixty-five thousand, eight hundred eighty".