28139832 has 128 divisors (see below), whose sum is σ = 91929600. Its totient is φ = 7807104.

The previous prime is 28139819. The next prime is 28139843. The reversal of 28139832 is 23893182.

It is a happy number.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55693 + ... + 56195.

It is an arithmetic number, because the mean of its divisors is an integer number (718200).

Almost surely, 2^28139832 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 28139832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45964800).

28139832 is an abundant number, since it is smaller than the sum of its proper divisors (63789768).

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

28139832 is a wasteful number, since it uses less digits than its factorization.

28139832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562 (or 552 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 28139832 is about 5304.6990489565. The cubic root of 28139832 is about 304.1635488849.

The spelling of 28139832 in words is "twenty-eight million, one hundred thirty-nine thousand, eight hundred thirty-two".