66905920128 has 64 divisors (see below), whose sum is σ = 183451749120. Its totient is φ = 21582551040.

The previous prime is 66905920121. The next prime is 66905920243. The reversal of 66905920128 is 82102950966.

66905920128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (66905920121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2798325 + ... + 2822132.

It is an arithmetic number, because the mean of its divisors is an integer number (2866433580).

Almost surely, 2^66905920128 is an apocalyptic number.

It is an amenable number.

66905920128 is an abundant number, since it is smaller than the sum of its proper divisors (116545828992).

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

66905920128 is a wasteful number, since it uses less digits than its factorization.

66905920128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5620505 (or 5620493 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 66905920128 in words is "sixty-six billion, nine hundred five million, nine hundred twenty thousand, one hundred twenty-eight".