27979209 has 8 divisors (see below), whose sum is σ = 41450720. Its totient is φ = 18652788.

The previous prime is 27979207. The next prime is 27979213. The reversal of 27979209 is 90297972.

It is not a de Polignac number, because 27979209 - 2¹ = 27979207 is a prime.

It is a super-2 number, since 2×27979209² = 1565672272531362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27979207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518107 + ... + 518160.

It is an arithmetic number, because the mean of its divisors is an integer number (5181340).

Almost surely, 2^27979209 is an apocalyptic number.

It is an amenable number.

27979209 is a deficient number, since it is larger than the sum of its proper divisors (13471511).

27979209 is a wasteful number, since it uses less digits than its factorization.

27979209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036276 (or 1036270 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 45.

The square root of 27979209 is about 5289.5376924642. The cubic root of 27979209 is about 303.5837193851.

The spelling of 27979209 in words is "twenty-seven million, nine hundred seventy-nine thousand, two hundred nine".