66783944 has 8 divisors (see below), whose sum is σ = 125219910. Its totient is φ = 33391968.

The previous prime is 66783923. The next prime is 66783947. The reversal of 66783944 is 44938766.

It can be written as a sum of positive squares in only one way, i.e., 61811044 + 4972900 = 7862^2 + 2230^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (66783947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4173989 + ... + 4174004.

Almost surely, 2^66783944 is an apocalyptic number.

It is an amenable number.

66783944 is a deficient number, since it is larger than the sum of its proper divisors (58435966).

66783944 is a wasteful number, since it uses less digits than its factorization.

66783944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8347999 (or 8347995 counting only the distinct ones).

The product of its digits is 870912, while the sum is 47.

The square root of 66783944 is about 8172.1443942211. The cubic root of 66783944 is about 405.7177618939.

The spelling of 66783944 in words is "sixty-six million, seven hundred eighty-three thousand, nine hundred forty-four".