27781675549 has 2 divisors, whose sum is σ = 27781675550. Its totient is φ = 27781675548.

The previous prime is 27781675543. The next prime is 27781675591. The reversal of 27781675549 is 94557618772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24717499524 + 3064176025 = 157218^2 + 55355^2 .

It is a cyclic number.

It is not a de Polignac number, because 27781675549 - 2⁵ = 27781675517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27781675543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13890837774 + 13890837775.

It is an arithmetic number, because the mean of its divisors is an integer number (13890837775).

Almost surely, 2^27781675549 is an apocalyptic number.

It is an amenable number.

27781675549 is a deficient number, since it is larger than the sum of its proper divisors (1).

27781675549 is an equidigital number, since it uses as much as digits as its factorization.

27781675549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29635200, while the sum is 61.

The spelling of 27781675549 in words is "twenty-seven billion, seven hundred eighty-one million, six hundred seventy-five thousand, five hundred forty-nine".