28218641 has 8 divisors (see below), whose sum is σ = 30833568. Its totient is φ = 25612000.

The previous prime is 28218637. The next prime is 28218719. The reversal of 28218641 is 14681282.

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 28218641 - 2² = 28218637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28218598 and 28218607.

It is not an unprimeable number, because it can be changed into a prime (28218611) 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, 6686 + ... + 10056.

It is an arithmetic number, because the mean of its divisors is an integer number (3854196).

Almost surely, 2^28218641 is an apocalyptic number.

It is an amenable number.

28218641 is a deficient number, since it is larger than the sum of its proper divisors (2614927).

28218641 is a wasteful number, since it uses less digits than its factorization.

28218641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4143.

The product of its digits is 6144, while the sum is 32.

The square root of 28218641 is about 5312.1220806755. The cubic root of 28218641 is about 304.4472331436.

The spelling of 28218641 in words is "twenty-eight million, two hundred eighteen thousand, six hundred forty-one".