166728818 has 4 divisors (see below), whose sum is σ = 250093230. Its totient is φ = 83364408.

The previous prime is 166728811. The next prime is 166728827. The reversal of 166728818 is 818827661.

It is a happy number.

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., 110733529 + 55995289 = 10523^2 + 7483^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166728811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41682203 + ... + 41682206.

Almost surely, 2^166728818 is an apocalyptic number.

166728818 is a deficient number, since it is larger than the sum of its proper divisors (83364412).

166728818 is an equidigital number, since it uses as much as digits as its factorization.

166728818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83364411.

The product of its digits is 258048, while the sum is 47.

The square root of 166728818 is about 12912.3513737816. The cubic root of 166728818 is about 550.3896060415.

The spelling of 166728818 in words is "one hundred sixty-six million, seven hundred twenty-eight thousand, eight hundred eighteen".