28199825 has 6 divisors (see below), whose sum is σ = 34967814. Its totient is φ = 22559840.

The previous prime is 28199807. The next prime is 28199833. The reversal of 28199825 is 52899182.

It can be written as a sum of positive squares in 3 ways, for example, as 1336336 + 26863489 = 1156^2 + 5183^2 .

It is not a de Polignac number, because 28199825 - 2⁸ = 28199569 is a prime.

It is a Duffinian 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 5 ways as a sum of consecutive naturals, for example, 563972 + ... + 564021.

It is an arithmetic number, because the mean of its divisors is an integer number (5827969).

Almost surely, 2^28199825 is an apocalyptic number.

28199825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28199825 is a deficient number, since it is larger than the sum of its proper divisors (6767989).

28199825 is a wasteful number, since it uses less digits than its factorization.

28199825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128003 (or 1127998 counting only the distinct ones).

The product of its digits is 103680, while the sum is 44.

The square root of 28199825 is about 5310.3507417119. The cubic root of 28199825 is about 304.3795503089.

The spelling of 28199825 in words is "twenty-eight million, one hundred ninety-nine thousand, eight hundred twenty-five".