66780764 has 6 divisors (see below), whose sum is σ = 116866344. Its totient is φ = 33390380.

The previous prime is 66780739. The next prime is 66780767. The reversal of 66780764 is 46708766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66780767) 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 as a sum of consecutive naturals, namely, 8347592 + ... + 8347599.

It is an arithmetic number, because the mean of its divisors is an integer number (19477724).

Almost surely, 2^66780764 is an apocalyptic number.

It is an amenable number.

66780764 is a deficient number, since it is larger than the sum of its proper divisors (50085580).

66780764 is a wasteful number, since it uses less digits than its factorization.

66780764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16695195 (or 16695193 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 44.

The square root of 66780764 is about 8171.9498285293. The cubic root of 66780764 is about 405.7113222075.

The spelling of 66780764 in words is "sixty-six million, seven hundred eighty thousand, seven hundred sixty-four".