166815639111389 has 2 divisors, whose sum is σ = 166815639111390. Its totient is φ = 166815639111388.

The previous prime is 166815639111379. The next prime is 166815639111409. The reversal of 166815639111389 is 983111936518661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163907642180164 + 2907996931225 = 12802642^2 + 1705285^2 .

It is a cyclic number.

It is not a de Polignac number, because 166815639111389 - 2²⁴ = 166815622334173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166815639111379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83407819555694 + 83407819555695.

It is an arithmetic number, because the mean of its divisors is an integer number (83407819555695).

Almost surely, 2^{166815639111389} is an apocalyptic number.

It is an amenable number.

166815639111389 is a deficient number, since it is larger than the sum of its proper divisors (1).

166815639111389 is an equidigital number, since it uses as much as digits as its factorization.

166815639111389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50388480, while the sum is 68.

The spelling of 166815639111389 in words is "one hundred sixty-six trillion, eight hundred fifteen billion, six hundred thirty-nine million, one hundred eleven thousand, three hundred eighty-nine".