27809145 has 48 divisors (see below), whose sum is σ = 59334912. Its totient is φ = 11733120.

The previous prime is 27809123. The next prime is 27809149. The reversal of 27809145 is 54190872.

It is not a de Polignac number, because 27809145 - 2⁵ = 27809113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (27809149) 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 47 ways as a sum of consecutive naturals, for example, 700 + ... + 7490.

It is an arithmetic number, because the mean of its divisors is an integer number (1236144).

Almost surely, 2^27809145 is an apocalyptic number.

It is an amenable number.

27809145 is an abundant number, since it is smaller than the sum of its proper divisors (31525767).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27809145 is a wasteful number, since it uses less digits than its factorization.

27809145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6822 (or 6819 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 27809145 is about 5273.4376833333. The cubic root of 27809145 is about 302.9673853076.

The spelling of 27809145 in words is "twenty-seven million, eight hundred nine thousand, one hundred forty-five".