28775140 has 24 divisors (see below), whose sum is σ = 61258680. Its totient is φ = 11351808.

The previous prime is 28775129. The next prime is 28775141. The reversal of 28775140 is 4157782.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3594816 + 25180324 = 1896^2 + 5018^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28775096 and 28775105.

It is not an unprimeable number, because it can be changed into a prime (28775141) 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 7 ways as a sum of consecutive naturals, for example, 8395 + ... + 11314.

It is an arithmetic number, because the mean of its divisors is an integer number (2552445).

Almost surely, 2^28775140 is an apocalyptic number.

28775140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28775140 is an abundant number, since it is smaller than the sum of its proper divisors (32483540).

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

28775140 is a wasteful number, since it uses less digits than its factorization.

28775140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19791 (or 19789 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 28775140 is about 5364.2464522056. The cubic root of 28775140 is about 306.4355510290.

The spelling of 28775140 in words is "twenty-eight million, seven hundred seventy-five thousand, one hundred forty".