166443506 has 4 divisors (see below), whose sum is σ = 249665262. Its totient is φ = 83221752.

The previous prime is 166443503. The next prime is 166443521. The reversal of 166443506 is 605344661.

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

It can be written as a sum of positive squares in only one way, i.e., 134351281 + 32092225 = 11591^2 + 5665^2 .

It is not an unprimeable number, because it can be changed into a prime (166443503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41610875 + ... + 41610878.

Almost surely, 2^166443506 is an apocalyptic number.

166443506 is a deficient number, since it is larger than the sum of its proper divisors (83221756).

166443506 is an equidigital number, since it uses as much as digits as its factorization.

166443506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83221755.

The product of its (nonzero) digits is 51840, while the sum is 35.

The square root of 166443506 is about 12901.2986168060. The cubic root of 166443506 is about 550.0754783466.

The spelling of 166443506 in words is "one hundred sixty-six million, four hundred forty-three thousand, five hundred six".