166381393 has 2 divisors, whose sum is σ = 166381394. Its totient is φ = 166381392.

The previous prime is 166381387. The next prime is 166381399. The reversal of 166381393 is 393183661.

It is a balanced prime because it is at equal distance from previous prime (166381387) and next prime (166381399).

It can be written as a sum of positive squares in only one way, i.e., 131606784 + 34774609 = 11472^2 + 5897^2 .

It is a cyclic number.

It is not a de Polignac number, because 166381393 - 2²⁵ = 132826961 is a prime.

It is not a weakly prime, because it can be changed into another prime (166381399) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83190696 + 83190697.

It is an arithmetic number, because the mean of its divisors is an integer number (83190697).

Almost surely, 2^166381393 is an apocalyptic number.

It is an amenable number.

166381393 is a deficient number, since it is larger than the sum of its proper divisors (1).

166381393 is an equidigital number, since it uses as much as digits as its factorization.

166381393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 40.

The square root of 166381393 is about 12898.8911538938. The cubic root of 166381393 is about 550.0070445379.

The spelling of 166381393 in words is "one hundred sixty-six million, three hundred eighty-one thousand, three hundred ninety-three".