28356440 has 32 divisors (see below), whose sum is σ = 72917280. Its totient is φ = 9722112.

The previous prime is 28356437. The next prime is 28356481. The reversal of 28356440 is 4465382.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28356397 and 28356406.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 50357 + ... + 50916.

It is an arithmetic number, because the mean of its divisors is an integer number (2278665).

Almost surely, 2^28356440 is an apocalyptic number.

28356440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28356440 is an abundant number, since it is smaller than the sum of its proper divisors (44560840).

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

28356440 is a wasteful number, since it uses less digits than its factorization.

28356440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101291 (or 101287 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 28356440 is about 5325.0765252717. The cubic root of 28356440 is about 304.9419938062.

The spelling of 28356440 in words is "twenty-eight million, three hundred fifty-six thousand, four hundred forty".