27864163885561 has 4 divisors (see below), whose sum is σ = 28389902826852. Its totient is φ = 27338424944272.

The previous prime is 27864163885511. The next prime is 27864163885573. The reversal of 27864163885561 is 16558836146872.

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 13662337987600 + 14201825897961 = 3696260^2 + 3768531^2 .

It is a cyclic number.

It is not a de Polignac number, because 27864163885561 - 2⁹ = 27864163885049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27864163885511) 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, 262869470566 + ... + 262869470671.

It is an arithmetic number, because the mean of its divisors is an integer number (7097475706713).

Almost surely, 2^{27864163885561} is an apocalyptic number.

It is an amenable number.

27864163885561 is a deficient number, since it is larger than the sum of its proper divisors (525738941291).

27864163885561 is an equidigital number, since it uses as much as digits as its factorization.

27864163885561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525738941290.

The product of its digits is 464486400, while the sum is 70.

The spelling of 27864163885561 in words is "twenty-seven trillion, eight hundred sixty-four billion, one hundred sixty-three million, eight hundred eighty-five thousand, five hundred sixty-one".