66444720164 has 24 divisors (see below), whose sum is σ = 116442768288. Its totient is φ = 33175396800.

The previous prime is 66444720143. The next prime is 66444720179. The reversal of 66444720164 is 46102744466.

It is a happy number.

It is an unprimeable number.

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, 10136312 + ... + 10142864.

It is an arithmetic number, because the mean of its divisors is an integer number (4851782012).

Almost surely, 2^66444720164 is an apocalyptic number.

It is an amenable number.

66444720164 is a deficient number, since it is larger than the sum of its proper divisors (49998048124).

66444720164 is a wasteful number, since it uses less digits than its factorization.

66444720164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9755 (or 9753 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 44.

The spelling of 66444720164 in words is "sixty-six billion, four hundred forty-four million, seven hundred twenty thousand, one hundred sixty-four".