64680440064 has 72 divisors (see below), whose sum is σ = 172240129152. Its totient is φ = 21548144640.

The previous prime is 64680440047. The next prime is 64680440089. The reversal of 64680440064 is 46004408646.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 64680439998 and 64680440025.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1414422 + ... + 1459434.

It is an arithmetic number, because the mean of its divisors is an integer number (2392224016).

Almost surely, 2^64680440064 is an apocalyptic number.

64680440064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64680440064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86120064576).

64680440064 is an abundant number, since it is smaller than the sum of its proper divisors (107559689088).

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

64680440064 is a wasteful number, since it uses less digits than its factorization.

64680440064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46903 (or 46889 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 42.

The spelling of 64680440064 in words is "sixty-four billion, six hundred eighty million, four hundred forty thousand, sixty-four".