166870393 has 4 divisors (see below), whose sum is σ = 166947748. Its totient is φ = 166793040.

The previous prime is 166870387. The next prime is 166870399. The reversal of 166870393 is 393078661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 393078661 = 193 ⋅2036677.

It is an interprime number because it is at equal distance from previous prime (166870387) and next prime (166870399).

It can be written as a sum of positive squares in 2 ways, for example, as 124255609 + 42614784 = 11147^2 + 6528^2 .

It is a cyclic number.

It is not a de Polignac number, because 166870393 - 2²⁵ = 133315961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166870399) 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 in 3 ways as a sum of consecutive naturals, for example, 35346 + ... + 39787.

It is an arithmetic number, because the mean of its divisors is an integer number (41736937).

Almost surely, 2^166870393 is an apocalyptic number.

It is an amenable number.

166870393 is a deficient number, since it is larger than the sum of its proper divisors (77355).

166870393 is an equidigital number, since it uses as much as digits as its factorization.

166870393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77354.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 166870393 is about 12917.8323646036. The cubic root of 166870393 is about 550.5453466918.

The spelling of 166870393 in words is "one hundred sixty-six million, eight hundred seventy thousand, three hundred ninety-three".