28504581 has 8 divisors (see below), whose sum is σ = 43435584. Its totient is φ = 16288320.

The previous prime is 28504577. The next prime is 28504601. The reversal of 28504581 is 18540582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28504581 - 2² = 28504577 is a prime.

It is a super-2 number, since 2×28504581² = 1625022275971122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28504501) 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, 678660 + ... + 678701.

It is an arithmetic number, because the mean of its divisors is an integer number (5429448).

Almost surely, 2^28504581 is an apocalyptic number.

28504581 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28504581 is a deficient number, since it is larger than the sum of its proper divisors (14931003).

28504581 is a wasteful number, since it uses less digits than its factorization.

28504581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1357371.

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 28504581 is about 5338.9681587363. The cubic root of 28504581 is about 305.4721023346.

The spelling of 28504581 in words is "twenty-eight million, five hundred four thousand, five hundred eighty-one".