27973527581 has 2 divisors, whose sum is σ = 27973527582. Its totient is φ = 27973527580.

The previous prime is 27973527577. The next prime is 27973527587. The reversal of 27973527581 is 18572537972.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27474720025 + 498807556 = 165755^2 + 22334^2 .

It is a cyclic number.

It is not a de Polignac number, because 27973527581 - 2² = 27973527577 is a prime.

It is a super-2 number, since 2×27973527581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27973527587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13986763790 + 13986763791.

It is an arithmetic number, because the mean of its divisors is an integer number (13986763791).

Almost surely, 2^27973527581 is an apocalyptic number.

It is an amenable number.

27973527581 is a deficient number, since it is larger than the sum of its proper divisors (1).

27973527581 is an equidigital number, since it uses as much as digits as its factorization.

27973527581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7408800, while the sum is 56.

The spelling of 27973527581 in words is "twenty-seven billion, nine hundred seventy-three million, five hundred twenty-seven thousand, five hundred eighty-one".