28218730 has 16 divisors (see below), whose sum is σ = 51010560. Its totient is φ = 11239312.

The previous prime is 28218727. The next prime is 28218731. The reversal of 28218730 is 3781282.

It is a junction number, because it is equal to n+sod(n) for n = 28218692 and 28218701.

It is not an unprimeable number, because it can be changed into a prime (28218731) 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, 3514 + ... + 8293.

It is an arithmetic number, because the mean of its divisors is an integer number (3188160).

Almost surely, 2^28218730 is an apocalyptic number.

28218730 is a deficient number, since it is larger than the sum of its proper divisors (22791830).

28218730 is a wasteful number, since it uses less digits than its factorization.

28218730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12053.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 28218730 is about 5312.1304577354. The cubic root of 28218730 is about 304.4475532131.

The spelling of 28218730 in words is "twenty-eight million, two hundred eighteen thousand, seven hundred thirty".