28984720 has 20 divisors (see below), whose sum is σ = 67389660. Its totient is φ = 11593856.

The previous prime is 28984691. The next prime is 28984733. The reversal of 28984720 is 2748982.

It can be written as a sum of positive squares in 2 ways, for example, as 15116544 + 13868176 = 3888^2 + 3724^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×28984720² = 1680227986956800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181075 + ... + 181234.

It is an arithmetic number, because the mean of its divisors is an integer number (3369483).

Almost surely, 2^28984720 is an apocalyptic number.

28984720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28984720 is an abundant number, since it is smaller than the sum of its proper divisors (38404940).

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

28984720 is a wasteful number, since it uses less digits than its factorization.

28984720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362322 (or 362316 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 28984720 is about 5383.7459078229. The cubic root of 28984720 is about 307.1777133174.

The spelling of 28984720 in words is "twenty-eight million, nine hundred eighty-four thousand, seven hundred twenty".