28643904 has 63 divisors (see below), whose sum is σ = 82472403. Its totient is φ = 9505152.

The previous prime is 28643897. The next prime is 28643917. The reversal of 28643904 is 40934682.

It is a happy number.

The square root of 28643904 is 5352.

It is a perfect power (a square), and thus also a powerful number.

28643904 is a `hidden beast` number, since 2 + 8 + 643 + 9 + 0 + 4 = 666.

It is a super-2 number, since 2×28643904² = 1640946472722432, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 128337 + ... + 128559.

Almost surely, 2^28643904 is an apocalyptic number.

28643904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

28643904 is the 5352-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28643904

28643904 is an abundant number, since it is smaller than the sum of its proper divisors (53828499).

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

28643904 is an equidigital number, since it uses as much as digits as its factorization.

28643904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 228 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The cubic root of 28643904 is about 305.9689831435.

Multiplying 28643904 by its sum of digits (36), we get a square (1031180544 = 32112²).

28643904 divided by its sum of digits (36) gives a square (795664 = 892²).

The spelling of 28643904 in words is "twenty-eight million, six hundred forty-three thousand, nine hundred four".