28145680 has 40 divisors (see below), whose sum is σ = 67042584. Its totient is φ = 10982400.

The previous prime is 28145671. The next prime is 28145683. The reversal of 28145680 is 8654182.

It can be written as a sum of positive squares in 4 ways, for example, as 3225616 + 24920064 = 1796^2 + 4992^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28145683) 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, 1011 + ... + 7570.

Almost surely, 2^28145680 is an apocalyptic number.

28145680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28145680 is an abundant number, since it is smaller than the sum of its proper divisors (38896904).

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

28145680 is a wasteful number, since it uses less digits than its factorization.

28145680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8635 (or 8629 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 28145680 is about 5305.2502297253. The cubic root of 28145680 is about 304.1846177767.

The spelling of 28145680 in words is "twenty-eight million, one hundred forty-five thousand, six hundred eighty".