27969785155217 has 2 divisors, whose sum is σ = 27969785155218. Its totient is φ = 27969785155216.

The previous prime is 27969785155171. The next prime is 27969785155229. The reversal of 27969785155217 is 71255158796972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27969723626881 + 61528336 = 5288641^2 + 7844^2 .

It is a cyclic number.

It is not a de Polignac number, because 27969785155217 - 2¹⁴ = 27969785138833 is a prime.

It is not a weakly prime, because it can be changed into another prime (27969785155267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13984892577608 + 13984892577609.

It is an arithmetic number, because the mean of its divisors is an integer number (13984892577609).

Almost surely, 2^{27969785155217} is an apocalyptic number.

It is an amenable number.

27969785155217 is a deficient number, since it is larger than the sum of its proper divisors (1).

27969785155217 is an equidigital number, since it uses as much as digits as its factorization.

27969785155217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 666792000, while the sum is 74.

The spelling of 27969785155217 in words is "twenty-seven trillion, nine hundred sixty-nine billion, seven hundred eighty-five million, one hundred fifty-five thousand, two hundred seventeen".