66544747 has 4 divisors (see below), whose sum is σ = 66711096. Its totient is φ = 66378400.

The previous prime is 66544703. The next prime is 66544769. The reversal of 66544747 is 74744566.

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 66544747 - 2¹¹ = 66542699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66544787) 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, 82573 + ... + 83374.

It is an arithmetic number, because the mean of its divisors is an integer number (16677774).

Almost surely, 2^66544747 is an apocalyptic number.

66544747 is a deficient number, since it is larger than the sum of its proper divisors (166349).

66544747 is a wasteful number, since it uses less digits than its factorization.

66544747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166348.

The product of its digits is 564480, while the sum is 43.

The square root of 66544747 is about 8157.4963683719. The cubic root of 66544747 is about 405.2328021911.

It can be divided in two parts, 665 and 44747, that multiplied together give a triangular number (29756755 = T₇₇₁₄).

The spelling of 66544747 in words is "sixty-six million, five hundred forty-four thousand, seven hundred forty-seven".