27561421 has 4 divisors (see below), whose sum is σ = 27614844. Its totient is φ = 27508000.

The previous prime is 27561407. The next prime is 27561433. The reversal of 27561421 is 12416572.

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 21058921 + 6502500 = 4589^2 + 2550^2 .

It is a cyclic number.

It is not a de Polignac number, because 27561421 - 2⁷ = 27561293 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27561421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27561481) 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, 25930 + ... + 26971.

It is an arithmetic number, because the mean of its divisors is an integer number (6903711).

Almost surely, 2^27561421 is an apocalyptic number.

It is an amenable number.

27561421 is a deficient number, since it is larger than the sum of its proper divisors (53423).

27561421 is an equidigital number, since it uses as much as digits as its factorization.

27561421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53422.

The product of its digits is 3360, while the sum is 28.

The square root of 27561421 is about 5249.8972370895. The cubic root of 27561421 is about 302.0650891093.

Adding to 27561421 its reverse (12416572), we get a palindrome (39977993).

The spelling of 27561421 in words is "twenty-seven million, five hundred sixty-one thousand, four hundred twenty-one".