27771641557 has 4 divisors (see below), whose sum is σ = 30296336256. Its totient is φ = 25246946860.

The previous prime is 27771641549. The next prime is 27771641591. The reversal of 27771641557 is 75514617772.

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 27771641557 - 2³ = 27771641549 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 (27775641557) 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, 1262347333 + ... + 1262347354.

It is an arithmetic number, because the mean of its divisors is an integer number (7574084064).

Almost surely, 2^27771641557 is an apocalyptic number.

It is an amenable number.

27771641557 is a deficient number, since it is larger than the sum of its proper divisors (2524694699).

27771641557 is a wasteful number, since it uses less digits than its factorization.

27771641557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2524694698.

The product of its digits is 2881200, while the sum is 52.

The spelling of 27771641557 in words is "twenty-seven billion, seven hundred seventy-one million, six hundred forty-one thousand, five hundred fifty-seven".