28728784 has 40 divisors (see below), whose sum is σ = 64013760. Its totient is φ = 12235008.

The previous prime is 28728769. The next prime is 28728787. The reversal of 28728784 is 48782782.

It is a super-3 number, since 3×28728784³ (a number of 23 digits) contains 333 as substring.

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

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28728787) 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, 19332 + ... + 20764.

It is an arithmetic number, because the mean of its divisors is an integer number (1600344).

Almost surely, 2^28728784 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 28728784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32006880).

28728784 is an abundant number, since it is smaller than the sum of its proper divisors (35284976).

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

28728784 is a wasteful number, since it uses less digits than its factorization.

28728784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627 (or 1621 counting only the distinct ones).

The product of its digits is 401408, while the sum is 46.

The square root of 28728784 is about 5359.9238800565. The cubic root of 28728784 is about 306.2709093595.

The spelling of 28728784 in words is "twenty-eight million, seven hundred twenty-eight thousand, seven hundred eighty-four".