28812187 has 4 divisors (see below), whose sum is σ = 28857640. Its totient is φ = 28766736.

The previous prime is 28812181. The next prime is 28812209. The reversal of 28812187 is 78121882.

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 28812187 - 2¹¹ = 28810139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28812181) 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, 21762 + ... + 23047.

It is an arithmetic number, because the mean of its divisors is an integer number (7214410).

Almost surely, 2^28812187 is an apocalyptic number.

28812187 is a deficient number, since it is larger than the sum of its proper divisors (45453).

28812187 is an equidigital number, since it uses as much as digits as its factorization.

28812187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45452.

The product of its digits is 14336, while the sum is 37.

The square root of 28812187 is about 5367.6984825901. The cubic root of 28812187 is about 306.5670030318.

The spelling of 28812187 in words is "twenty-eight million, eight hundred twelve thousand, one hundred eighty-seven".