66998185 has 4 divisors (see below), whose sum is σ = 80397828. Its totient is φ = 53598544.

The previous prime is 66998177. The next prime is 66998189. The reversal of 66998185 is 58189966.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20034576 + 46963609 = 4476^2 + 6853^2 .

It is a cyclic number.

It is not a de Polignac number, because 66998185 - 2³ = 66998177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66998189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6699814 + ... + 6699823.

It is an arithmetic number, because the mean of its divisors is an integer number (20099457).

Almost surely, 2^66998185 is an apocalyptic number.

It is an amenable number.

66998185 is a deficient number, since it is larger than the sum of its proper divisors (13399643).

66998185 is a wasteful number, since it uses less digits than its factorization.

66998185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13399642.

The product of its digits is 933120, while the sum is 52.

The square root of 66998185 is about 8185.2419023508. The cubic root of 66998185 is about 406.1511424941.

It can be divided in two parts, 6699 and 8185, that added together give a square (14884 = 122²).

The spelling of 66998185 in words is "sixty-six million, nine hundred ninety-eight thousand, one hundred eighty-five".