28866440 has 16 divisors (see below), whose sum is σ = 64949580. Its totient is φ = 11546560.

The previous prime is 28866433. The next prime is 28866443. The reversal of 28866440 is 4466882.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 28536964 + 329476 = 5342^2 + 574^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28866394 and 28866403.

It is not an unprimeable number, because it can be changed into a prime (28866443) 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 3 ways as a sum of consecutive naturals, for example, 360791 + ... + 360870.

Almost surely, 2^28866440 is an apocalyptic number.

28866440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28866440 is an abundant number, since it is smaller than the sum of its proper divisors (36083140).

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

28866440 is a wasteful number, since it uses less digits than its factorization.

28866440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721672 (or 721668 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 38.

The square root of 28866440 is about 5372.7497615281. The cubic root of 28866440 is about 306.7593030369.

The spelling of 28866440 in words is "twenty-eight million, eight hundred sixty-six thousand, four hundred forty".