66994189 has 4 divisors (see below), whose sum is σ = 67010560. Its totient is φ = 66977820.

The previous prime is 66994177. The next prime is 66994199. The reversal of 66994189 is 98149966.

66994189 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 98149966 = 2 ⋅49074983.

It is a cyclic number.

It is not a de Polignac number, because 66994189 - 2⁷ = 66994061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66994199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4084 + ... + 12274.

It is an arithmetic number, because the mean of its divisors is an integer number (16752640).

Almost surely, 2^66994189 is an apocalyptic number.

It is an amenable number.

66994189 is a deficient number, since it is larger than the sum of its proper divisors (16371).

66994189 is an equidigital number, since it uses as much as digits as its factorization.

66994189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16370.

The product of its digits is 839808, while the sum is 52.

The square root of 66994189 is about 8184.9978008549. The cubic root of 66994189 is about 406.1430675877.

The spelling of 66994189 in words is "sixty-six million, nine hundred ninety-four thousand, one hundred eighty-nine".