27989281 has 4 divisors (see below), whose sum is σ = 28008112. Its totient is φ = 27970452.

The previous prime is 27989251. The next prime is 27989287. The reversal of 27989281 is 18298972.

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.

It is a cyclic number.

It is not a de Polignac number, because 27989281 - 2⁷ = 27989153 is a prime.

It is a super-2 number, since 2×27989281² = 1566799701793922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27989287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6975 + ... + 10228.

It is an arithmetic number, because the mean of its divisors is an integer number (7002028).

Almost surely, 2^27989281 is an apocalyptic number.

It is an amenable number.

27989281 is a deficient number, since it is larger than the sum of its proper divisors (18831).

27989281 is a wasteful number, since it uses less digits than its factorization.

27989281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18830.

The product of its digits is 145152, while the sum is 46.

The square root of 27989281 is about 5290.4896748789. The cubic root of 27989281 is about 303.6201431976.

It can be divided in two parts, 2798928 and 1, that added together give a square (2798929 = 1673²).

The spelling of 27989281 in words is "twenty-seven million, nine hundred eighty-nine thousand, two hundred eighty-one".