28158732 has 144 divisors (see below), whose sum is σ = 90205920. Its totient is φ = 7547904.

The previous prime is 28158727. The next prime is 28158737. The reversal of 28158732 is 23785182.

It is an interprime number because it is at equal distance from previous prime (28158727) and next prime (28158737).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28158737) 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 47 ways as a sum of consecutive naturals, for example, 89808 + ... + 90120.

It is an arithmetic number, because the mean of its divisors is an integer number (626430).

Almost surely, 2^28158732 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28158732, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45102960).

28158732 is an abundant number, since it is smaller than the sum of its proper divisors (62047188).

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

28158732 is a wasteful number, since it uses less digits than its factorization.

28158732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 342 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 28158732 is about 5306.4801893534. The cubic root of 28158732 is about 304.2316303684.

The spelling of 28158732 in words is "twenty-eight million, one hundred fifty-eight thousand, seven hundred thirty-two".