27919809 has 20 divisors (see below), whose sum is σ = 43056640. Its totient is φ = 18011160.

The previous prime is 27919777. The next prime is 27919813. The reversal of 27919809 is 90891972.

It is not a de Polignac number, because 27919809 - 2⁵ = 27919777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27919849) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3049 + ... + 8070.

It is an arithmetic number, because the mean of its divisors is an integer number (2152832).

Almost surely, 2^27919809 is an apocalyptic number.

It is an amenable number.

27919809 is a deficient number, since it is larger than the sum of its proper divisors (15136831).

27919809 is a wasteful number, since it uses less digits than its factorization.

27919809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11162 (or 11153 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 27919809 is about 5283.9198517767. The cubic root of 27919809 is about 303.3687305899.

The spelling of 27919809 in words is "twenty-seven million, nine hundred nineteen thousand, eight hundred nine".