66189998 has 16 divisors (see below), whose sum is σ = 118402560. Its totient is φ = 27133656.

The previous prime is 66189997. The next prime is 66190001. The reversal of 66189998 is 89998166.

It is a super-2 number, since 2×66189998² = 8762231670480008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66189997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102458 + ... + 103101.

It is an arithmetic number, because the mean of its divisors is an integer number (7400160).

Almost surely, 2^66189998 is an apocalyptic number.

66189998 is a deficient number, since it is larger than the sum of its proper divisors (52212562).

66189998 is a wasteful number, since it uses less digits than its factorization.

66189998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205591.

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

The square root of 66189998 is about 8135.7235695419. The cubic root of 66189998 is about 404.5114222143.

The spelling of 66189998 in words is "sixty-six million, one hundred eighty-nine thousand, nine hundred ninety-eight".