28406784 has 88 divisors (see below), whose sum is σ = 86596288. Its totient is φ = 8110080.

The previous prime is 28406783. The next prime is 28406797. The reversal of 28406784 is 48760482.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28406783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20844 + ... + 22164.

Almost surely, 2^28406784 is an apocalyptic number.

28406784 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 28406784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43298144).

28406784 is an abundant number, since it is smaller than the sum of its proper divisors (58189504).

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

28406784 is a wasteful number, since it uses less digits than its factorization.

28406784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1351 (or 1333 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 39.

The square root of 28406784 is about 5329.8014972417. The cubic root of 28406784 is about 305.1223517000.

The spelling of 28406784 in words is "twenty-eight million, four hundred six thousand, seven hundred eighty-four".