28870247 has 4 divisors (see below), whose sum is σ = 32994576. Its totient is φ = 24745920.

The previous prime is 28870241. The next prime is 28870279. The reversal of 28870247 is 74207882.

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

It is a cyclic number.

It is not a de Polignac number, because 28870247 - 2⁶ = 28870183 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28870247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28870241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2062154 + ... + 2062167.

It is an arithmetic number, because the mean of its divisors is an integer number (8248644).

Almost surely, 2^28870247 is an apocalyptic number.

28870247 is a deficient number, since it is larger than the sum of its proper divisors (4124329).

28870247 is an equidigital number, since it uses as much as digits as its factorization.

28870247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4124328.

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 28870247 is about 5373.1040377048. The cubic root of 28870247 is about 306.7727879157.

The spelling of 28870247 in words is "twenty-eight million, eight hundred seventy thousand, two hundred forty-seven".