28734840 has 96 divisors (see below), whose sum is σ = 98326800. Its totient is φ = 7257600.

The previous prime is 28734787. The next prime is 28734841. The reversal of 28734840 is 4843782.

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

It is a junction number, because it is equal to n+sod(n) for n = 28734795 and 28734804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28734841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4740 + ... + 8940.

Almost surely, 2^28734840 is an apocalyptic number.

28734840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28734840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49163400).

28734840 is an abundant number, since it is smaller than the sum of its proper divisors (69591960).

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

28734840 is a wasteful number, since it uses less digits than its factorization.

28734840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4237 (or 4230 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The square root of 28734840 is about 5360.4887836838. The cubic root of 28734840 is about 306.2924283851.

The spelling of 28734840 in words is "twenty-eight million, seven hundred thirty-four thousand, eight hundred forty".