166978018 has 4 divisors (see below), whose sum is σ = 250467030. Its totient is φ = 83489008.

The previous prime is 166977991. The next prime is 166978033. The reversal of 166978018 is 810879661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 810879661 = 1511 ⋅536651.

It can be written as a sum of positive squares in only one way, i.e., 154678969 + 12299049 = 12437^2 + 3507^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41744503 + ... + 41744506.

Almost surely, 2^166978018 is an apocalyptic number.

166978018 is a deficient number, since it is larger than the sum of its proper divisors (83489012).

166978018 is an equidigital number, since it uses as much as digits as its factorization.

166978018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83489011.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 166978018 is about 12921.9974462155. The cubic root of 166978018 is about 550.6636814623.

The spelling of 166978018 in words is "one hundred sixty-six million, nine hundred seventy-eight thousand, eighteen".