66745671 has 4 divisors (see below), whose sum is σ = 88994232. Its totient is φ = 44497112.

The previous prime is 66745667. The next prime is 66745681. The reversal of 66745671 is 17654766.

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 66745671 - 2² = 66745667 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66745631) 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, 11124276 + ... + 11124281.

It is an arithmetic number, because the mean of its divisors is an integer number (22248558).

Almost surely, 2^66745671 is an apocalyptic number.

66745671 is a deficient number, since it is larger than the sum of its proper divisors (22248561).

66745671 is a wasteful number, since it uses less digits than its factorization.

66745671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22248560.

The product of its digits is 211680, while the sum is 42.

The square root of 66745671 is about 8169.8023843909. The cubic root of 66745671 is about 405.6402432458.

The spelling of 66745671 in words is "sixty-six million, seven hundred forty-five thousand, six hundred seventy-one".