27731144557 has 2 divisors, whose sum is σ = 27731144558. Its totient is φ = 27731144556.

The previous prime is 27731144533. The next prime is 27731144561. The reversal of 27731144557 is 75544113772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18531649161 + 9199495396 = 136131^2 + 95914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27731144557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27731144587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13865572278 + 13865572279.

It is an arithmetic number, because the mean of its divisors is an integer number (13865572279).

Almost surely, 2^27731144557 is an apocalyptic number.

It is an amenable number.

27731144557 is a deficient number, since it is larger than the sum of its proper divisors (1).

27731144557 is an equidigital number, since it uses as much as digits as its factorization.

27731144557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 823200, while the sum is 46.

The spelling of 27731144557 in words is "twenty-seven billion, seven hundred thirty-one million, one hundred forty-four thousand, five hundred fifty-seven".