28784664 has 24 divisors (see below), whose sum is σ = 77958660. Its totient is φ = 9594864.

The previous prime is 28784663. The next prime is 28784683. The reversal of 28784664 is 46648782.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28784663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 199822 + ... + 199965.

Almost surely, 2^28784664 is an apocalyptic number.

28784664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28784664 is an abundant number, since it is smaller than the sum of its proper divisors (49173996).

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

28784664 is a wasteful number, since it uses less digits than its factorization.

28784664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399799 (or 399792 counting only the distinct ones).

The product of its digits is 516096, while the sum is 45.

The square root of 28784664 is about 5365.1341082959. The cubic root of 28784664 is about 306.4693553274.

The spelling of 28784664 in words is "twenty-eight million, seven hundred eighty-four thousand, six hundred sixty-four".