166404643 has 4 divisors (see below), whose sum is σ = 166660128. Its totient is φ = 166149160.

The previous prime is 166404631. The next prime is 166404649. The reversal of 166404643 is 346404661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166404643 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166404599 and 166404608.

It is not an unprimeable number, because it can be changed into a prime (166404649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126763 + ... + 128068.

It is an arithmetic number, because the mean of its divisors is an integer number (41665032).

Almost surely, 2^166404643 is an apocalyptic number.

166404643 is a deficient number, since it is larger than the sum of its proper divisors (255485).

166404643 is an equidigital number, since it uses as much as digits as its factorization.

166404643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255484.

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 166404643 is about 12899.7923626700. The cubic root of 166404643 is about 550.0326625231.

The spelling of 166404643 in words is "one hundred sixty-six million, four hundred four thousand, six hundred forty-three".