27887581261 has 4 divisors (see below), whose sum is σ = 27889227612. Its totient is φ = 27885934912.

The previous prime is 27887581231. The next prime is 27887581283. The reversal of 27887581261 is 16218578872.

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 21622500 + 27865958761 = 4650^2 + 166931^2 .

It is a cyclic number.

It is not a de Polignac number, because 27887581261 - 2⁵ = 27887581229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27887581231) 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, 797500 + ... + 831733.

It is an arithmetic number, because the mean of its divisors is an integer number (6972306903).

Almost surely, 2^27887581261 is an apocalyptic number.

It is an amenable number.

27887581261 is a deficient number, since it is larger than the sum of its proper divisors (1646351).

27887581261 is a wasteful number, since it uses less digits than its factorization.

27887581261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1646350.

The product of its digits is 3010560, while the sum is 55.

The spelling of 27887581261 in words is "twenty-seven billion, eight hundred eighty-seven million, five hundred eighty-one thousand, two hundred sixty-one".