66189899 has 4 divisors (see below), whose sum is σ = 66596136. Its totient is φ = 65783664.

The previous prime is 66189889. The next prime is 66189911. The reversal of 66189899 is 99898166.

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

It is a cyclic number.

It is not a de Polignac number, because 66189899 - 2¹² = 66185803 is a prime.

It is a super-2 number, since 2×66189899² = 8762205459260402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66189829) 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, 202874 + ... + 203199.

It is an arithmetic number, because the mean of its divisors is an integer number (16649034).

Almost surely, 2^66189899 is an apocalyptic number.

66189899 is a deficient number, since it is larger than the sum of its proper divisors (406237).

66189899 is a wasteful number, since it uses less digits than its factorization.

66189899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406236.

The product of its digits is 1679616, while the sum is 56.

The square root of 66189899 is about 8135.7174852621. The cubic root of 66189899 is about 404.5112205391.

The spelling of 66189899 in words is "sixty-six million, one hundred eighty-nine thousand, eight hundred ninety-nine".