27946978517 has 2 divisors, whose sum is σ = 27946978518. Its totient is φ = 27946978516.

The previous prime is 27946978441. The next prime is 27946978537. The reversal of 27946978517 is 71587964972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26987589841 + 959388676 = 164279^2 + 30974^2 .

It is a cyclic number.

It is not a de Polignac number, because 27946978517 - 2¹⁸ = 27946716373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27946978537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13973489258 + 13973489259.

It is an arithmetic number, because the mean of its divisors is an integer number (13973489259).

Almost surely, 2^27946978517 is an apocalyptic number.

It is an amenable number.

27946978517 is a deficient number, since it is larger than the sum of its proper divisors (1).

27946978517 is an equidigital number, since it uses as much as digits as its factorization.

27946978517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 53343360, while the sum is 65.

The spelling of 27946978517 in words is "twenty-seven billion, nine hundred forty-six million, nine hundred seventy-eight thousand, five hundred seventeen".