66724189 has 4 divisors (see below), whose sum is σ = 76256224. Its totient is φ = 57192156.

The previous prime is 66724171. The next prime is 66724199. The reversal of 66724189 is 98142766.

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.

It is not a de Polignac number, because 66724189 - 2⁹ = 66723677 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 (66724109) 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, 4766007 + ... + 4766020.

It is an arithmetic number, because the mean of its divisors is an integer number (19064056).

Almost surely, 2^66724189 is an apocalyptic number.

It is an amenable number.

66724189 is a deficient number, since it is larger than the sum of its proper divisors (9532035).

66724189 is an equidigital number, since it uses as much as digits as its factorization.

66724189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9532034.

The product of its digits is 145152, while the sum is 43.

The square root of 66724189 is about 8168.4875589059. The cubic root of 66724189 is about 405.5967203297.

The spelling of 66724189 in words is "sixty-six million, seven hundred twenty-four thousand, one hundred eighty-nine".