27887989 has 4 divisors (see below), whose sum is σ = 27899424. Its totient is φ = 27876556.

The previous prime is 27887947. The next prime is 27887999. The reversal of 27887989 is 98978872.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 27887989 - 2¹⁵ = 27855221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27887999) 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, 427 + ... + 7480.

It is an arithmetic number, because the mean of its divisors is an integer number (6974856).

Almost surely, 2^27887989 is an apocalyptic number.

It is an amenable number.

27887989 is a deficient number, since it is larger than the sum of its proper divisors (11435).

27887989 is an equidigital number, since it uses as much as digits as its factorization.

27887989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11434.

The product of its digits is 4064256, while the sum is 58.

The square root of 27887989 is about 5280.9079711731. The cubic root of 27887989 is about 303.2534377458.

The spelling of 27887989 in words is "twenty-seven million, eight hundred eighty-seven thousand, nine hundred eighty-nine".