28543681 has 8 divisors (see below), whose sum is σ = 30248000. Its totient is φ = 26859600.

The previous prime is 28543679. The next prime is 28543693. The reversal of 28543681 is 18634582.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28543681 - 2¹ = 28543679 is a prime.

It is a super-2 number, since 2×28543681² = 1629483450059522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28543681.

It is not an unprimeable number, because it can be changed into a prime (28543651) 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, 2106 + ... + 7843.

It is an arithmetic number, because the mean of its divisors is an integer number (3781000).

Almost surely, 2^28543681 is an apocalyptic number.

It is an amenable number.

28543681 is a deficient number, since it is larger than the sum of its proper divisors (1704319).

28543681 is a wasteful number, since it uses less digits than its factorization.

28543681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10119.

The product of its digits is 46080, while the sum is 37.

The square root of 28543681 is about 5342.6286601260. The cubic root of 28543681 is about 305.6117114983.

Subtracting from 28543681 its reverse (18634582), we obtain a palindrome (9909099).

The spelling of 28543681 in words is "twenty-eight million, five hundred forty-three thousand, six hundred eighty-one".