66738763680 has 48 divisors (see below), whose sum is σ = 210227107104. Its totient is φ = 17797003520.

The previous prime is 66738763639. The next prime is 66738763687. The reversal of 66738763680 is 8636783766.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (66738763687) 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 7 ways as a sum of consecutive naturals, for example, 69519066 + ... + 69520025.

It is an arithmetic number, because the mean of its divisors is an integer number (4379731398).

Almost surely, 2^66738763680 is an apocalyptic number.

66738763680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66738763680 is an abundant number, since it is smaller than the sum of its proper divisors (143488343424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66738763680 is a wasteful number, since it uses less digits than its factorization.

66738763680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139039109 (or 139039101 counting only the distinct ones).

The product of its (nonzero) digits is 36578304, while the sum is 60.

The spelling of 66738763680 in words is "sixty-six billion, seven hundred thirty-eight million, seven hundred sixty-three thousand, six hundred eighty".