27768326561 has 4 divisors (see below), whose sum is σ = 28159429824. Its totient is φ = 27377223300.

The previous prime is 27768326557. The next prime is 27768326563. The reversal of 27768326561 is 16562386772.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 27768326561 - 2² = 27768326557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27768326563) 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, 195551525 + ... + 195551666.

It is an arithmetic number, because the mean of its divisors is an integer number (7039857456).

Almost surely, 2^27768326561 is an apocalyptic number.

It is an amenable number.

27768326561 is a deficient number, since it is larger than the sum of its proper divisors (391103263).

27768326561 is an equidigital number, since it uses as much as digits as its factorization.

27768326561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391103262.

The product of its digits is 5080320, while the sum is 53.

The spelling of 27768326561 in words is "twenty-seven billion, seven hundred sixty-eight million, three hundred twenty-six thousand, five hundred sixty-one".