28218747 has 4 divisors (see below), whose sum is σ = 37625000. Its totient is φ = 18812496.

The previous prime is 28218739. The next prime is 28218761. The reversal of 28218747 is 74781282.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28218747 - 2³ = 28218739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28218727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4703122 + ... + 4703127.

It is an arithmetic number, because the mean of its divisors is an integer number (9406250).

Almost surely, 2^28218747 is an apocalyptic number.

28218747 is a deficient number, since it is larger than the sum of its proper divisors (9406253).

28218747 is an equidigital number, since it uses as much as digits as its factorization.

28218747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9406252.

The product of its digits is 50176, while the sum is 39.

The square root of 28218747 is about 5312.1320578465. The cubic root of 28218747 is about 304.4476143499.

The spelling of 28218747 in words is "twenty-eight million, two hundred eighteen thousand, seven hundred forty-seven".