28131708 has 24 divisors (see below), whose sum is σ = 71608320. Its totient is φ = 8524720.

The previous prime is 28131707. The next prime is 28131713. The reversal of 28131708 is 80713182.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28131707) 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, 106428 + ... + 106691.

It is an arithmetic number, because the mean of its divisors is an integer number (2983680).

Almost surely, 2^28131708 is an apocalyptic number.

It is an amenable number.

28131708 is an abundant number, since it is smaller than the sum of its proper divisors (43476612).

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

28131708 is a wasteful number, since it uses less digits than its factorization.

28131708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213137 (or 213135 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 28131708 is about 5303.9332574986. The cubic root of 28131708 is about 304.1342752855.

The spelling of 28131708 in words is "twenty-eight million, one hundred thirty-one thousand, seven hundred eight".