28691784 has 96 divisors (see below), whose sum is σ = 89799840. Its totient is φ = 8179200.

The previous prime is 28691753. The next prime is 28691837. The reversal of 28691784 is 48719682.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 12399 + ... + 14529.

It is an arithmetic number, because the mean of its divisors is an integer number (935415).

Almost surely, 2^28691784 is an apocalyptic number.

28691784 is a gapful number since it is divisible by the number (24) 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 28691784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44899920).

28691784 is an abundant number, since it is smaller than the sum of its proper divisors (61108056).

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

28691784 is a wasteful number, since it uses less digits than its factorization.

28691784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2171 (or 2164 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 28691784 is about 5356.4712264699. The cubic root of 28691784 is about 306.1393700644.

The spelling of 28691784 in words is "twenty-eight million, six hundred ninety-one thousand, seven hundred eighty-four".