66971743 has 4 divisors (see below), whose sum is σ = 67190200. Its totient is φ = 66753288.

The previous prime is 66971741. The next prime is 66971761. The reversal of 66971743 is 34717966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34717966 = 2 ⋅17358983.

It is a cyclic number.

It is not a de Polignac number, because 66971743 - 2¹ = 66971741 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66971743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66971741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108768 + ... + 109381.

It is an arithmetic number, because the mean of its divisors is an integer number (16797550).

Almost surely, 2^66971743 is an apocalyptic number.

66971743 is a deficient number, since it is larger than the sum of its proper divisors (218457).

66971743 is a wasteful number, since it uses less digits than its factorization.

66971743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218456.

The product of its digits is 190512, while the sum is 43.

The square root of 66971743 is about 8183.6265188485. The cubic root of 66971743 is about 406.0977039238.

The spelling of 66971743 in words is "sixty-six million, nine hundred seventy-one thousand, seven hundred forty-three".