27745561 has 4 divisors (see below), whose sum is σ = 28422324. Its totient is φ = 27068800.

The previous prime is 27745559. The next prime is 27745573. The reversal of 27745561 is 16554772.

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 6760000 + 20985561 = 2600^2 + 4581^2 .

It is a cyclic number.

It is not a de Polignac number, because 27745561 - 2¹ = 27745559 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 27745561.

It is not an unprimeable number, because it can be changed into a prime (27745261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 338320 + ... + 338401.

It is an arithmetic number, because the mean of its divisors is an integer number (7105581).

Almost surely, 2^27745561 is an apocalyptic number.

It is an amenable number.

27745561 is a deficient number, since it is larger than the sum of its proper divisors (676763).

27745561 is an equidigital number, since it uses as much as digits as its factorization.

27745561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676762.

The product of its digits is 58800, while the sum is 37.

The square root of 27745561 is about 5267.4055283413. The cubic root of 27745561 is about 302.7363033042.

The spelling of 27745561 in words is "twenty-seven million, seven hundred forty-five thousand, five hundred sixty-one".