66744784 has 20 divisors (see below), whose sum is σ = 130070916. Its totient is φ = 33178112.

The previous prime is 66744779. The next prime is 66744787. The reversal of 66744784 is 48744766.

It can be written as a sum of positive squares in 2 ways, for example, as 53582400 + 13162384 = 7320^2 + 3628^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66744787) 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, 9289 + ... + 14824.

Almost surely, 2^66744784 is an apocalyptic number.

It is an amenable number.

66744784 is a deficient number, since it is larger than the sum of its proper divisors (63326132).

66744784 is a wasteful number, since it uses less digits than its factorization.

66744784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24294 (or 24288 counting only the distinct ones).

The product of its digits is 903168, while the sum is 46.

The square root of 66744784 is about 8169.7480989318. The cubic root of 66744784 is about 405.6384463528.

It can be divided in two parts, 66744 and 784, that added together give a triangular number (67528 = T₃₆₇).

The spelling of 66744784 in words is "sixty-six million, seven hundred forty-four thousand, seven hundred eighty-four".