64368546640 has 80 divisors (see below), whose sum is σ = 152605442448. Its totient is φ = 25240936448.

The previous prime is 64368546623. The next prime is 64368546667. The reversal of 64368546640 is 4664586346.

64368546640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 2882401344 + 61486145296 = 53688^2 + 247964^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5815992 + ... + 5827048.

Almost surely, 2^64368546640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64368546640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76302721224).

64368546640 is an abundant number, since it is smaller than the sum of its proper divisors (88236895808).

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

64368546640 is a wasteful number, since it uses less digits than its factorization.

64368546640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12496 (or 12490 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 52.

The spelling of 64368546640 in words is "sixty-four billion, three hundred sixty-eight million, five hundred forty-six thousand, six hundred forty".