28129320 has 48 divisors (see below), whose sum is σ = 91421460. Its totient is φ = 7501056.

The previous prime is 28129301. The next prime is 28129393. The reversal of 28129320 is 2392182.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 28068804 + 60516 = 5298^2 + 246^2 .

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 38709 + ... + 39428.

Almost surely, 2^28129320 is an apocalyptic number.

28129320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28129320 is an abundant number, since it is smaller than the sum of its proper divisors (63292140).

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

28129320 is a wasteful number, since it uses less digits than its factorization.

28129320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78154 (or 78147 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 28129320 is about 5303.7081367662. The cubic root of 28129320 is about 304.1256694186.

The spelling of 28129320 in words is "twenty-eight million, one hundred twenty-nine thousand, three hundred twenty".