64626289728 has 672 divisors, whose sum is σ = 236205906048. Its totient is φ = 15455784960.

The previous prime is 64626289703. The next prime is 64626289733. The reversal of 64626289728 is 82798262646.

It is a tau number, because it is divible by the number of its divisors (672).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 162786426 + ... + 162786822.

It is an arithmetic number, because the mean of its divisors is an integer number (351496884).

Almost surely, 2^64626289728 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 64626289728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118102953024).

64626289728 is an abundant number, since it is smaller than the sum of its proper divisors (171579616320).

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

64626289728 is a wasteful number, since it uses less digits than its factorization.

64626289728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 433 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 60.

The spelling of 64626289728 in words is "sixty-four billion, six hundred twenty-six million, two hundred eighty-nine thousand, seven hundred twenty-eight".