28408940 has 24 divisors (see below), whose sum is σ = 68181792. Its totient is φ = 9740160.

The previous prime is 28408931. The next prime is 28408943. The reversal of 28408940 is 4980482.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 28408940.

It is not an unprimeable number, because it can be changed into a prime (28408943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101321 + ... + 101600.

It is an arithmetic number, because the mean of its divisors is an integer number (2840908).

Almost surely, 2^28408940 is an apocalyptic number.

28408940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28408940 is an abundant number, since it is smaller than the sum of its proper divisors (39772852).

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

28408940 is a wasteful number, since it uses less digits than its factorization.

28408940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202937 (or 202935 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 28408940 is about 5330.0037523439. The cubic root of 28408940 is about 305.1300708320.

The spelling of 28408940 in words is "twenty-eight million, four hundred eight thousand, nine hundred forty".