66840804064 has 24 divisors (see below), whose sum is σ = 138518772840. Its totient is φ = 31661433216.

The previous prime is 66840804053. The next prime is 66840804067. The reversal of 66840804064 is 46040804866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66840804067) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54967159 + ... + 54968374.

It is an arithmetic number, because the mean of its divisors is an integer number (5771615535).

Almost surely, 2^66840804064 is an apocalyptic number.

It is an amenable number.

66840804064 is an abundant number, since it is smaller than the sum of its proper divisors (71677968776).

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

66840804064 is a wasteful number, since it uses less digits than its factorization.

66840804064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109935562 (or 109935554 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 46.

The spelling of 66840804064 in words is "sixty-six billion, eight hundred forty million, eight hundred four thousand, sixty-four".