166038391 has 2 divisors, whose sum is σ = 166038392. Its totient is φ = 166038390.

The previous prime is 166038377. The next prime is 166038407. The reversal of 166038391 is 193830661.

It is a weak prime.

It is an emirp because it is prime and its reverse (193830661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166038391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166038391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166038361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83019195 + 83019196.

It is an arithmetic number, because the mean of its divisors is an integer number (83019196).

Almost surely, 2^166038391 is an apocalyptic number.

166038391 is a deficient number, since it is larger than the sum of its proper divisors (1).

166038391 is an equidigital number, since it uses as much as digits as its factorization.

166038391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 166038391 is about 12885.5885003363. The cubic root of 166038391 is about 549.6288305631.

The spelling of 166038391 in words is "one hundred sixty-six million, thirty-eight thousand, three hundred ninety-one".