27161221 has 4 divisors (see below), whose sum is σ = 27185932. Its totient is φ = 27136512.

The previous prime is 27161213. The next prime is 27161237. The reversal of 27161221 is 12216172.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7924225 + 19236996 = 2815^2 + 4386^2 .

It is a cyclic number.

It is not a de Polignac number, because 27161221 - 2³ = 27161213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 27161192 and 27161201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27161521) 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, 10626 + ... + 12931.

It is an arithmetic number, because the mean of its divisors is an integer number (6796483).

Almost surely, 2^27161221 is an apocalyptic number.

It is an amenable number.

27161221 is a deficient number, since it is larger than the sum of its proper divisors (24711).

27161221 is a wasteful number, since it uses less digits than its factorization.

27161221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24710.

The product of its digits is 336, while the sum is 22.

The square root of 27161221 is about 5211.6428312002. The cubic root of 27161221 is about 300.5959302548.

Adding to 27161221 its reverse (12216172), we get a palindrome (39377393).

The spelling of 27161221 in words is "twenty-seven million, one hundred sixty-one thousand, two hundred twenty-one".