27687658643 has 2 divisors, whose sum is σ = 27687658644. Its totient is φ = 27687658642.

The previous prime is 27687658639. The next prime is 27687658657. The reversal of 27687658643 is 34685678672.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 27687658643 - 2² = 27687658639 is a prime.

It is a super-2 number, since 2×27687658643² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (27687658673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13843829321 + 13843829322.

It is an arithmetic number, because the mean of its divisors is an integer number (13843829322).

Almost surely, 2^27687658643 is an apocalyptic number.

27687658643 is a deficient number, since it is larger than the sum of its proper divisors (1).

27687658643 is an equidigital number, since it uses as much as digits as its factorization.

27687658643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81285120, while the sum is 62.

The spelling of 27687658643 in words is "twenty-seven billion, six hundred eighty-seven million, six hundred fifty-eight thousand, six hundred forty-three".