64993840128 has 880 divisors, whose sum is σ = 240442650624. Its totient is φ = 17079828480.

The previous prime is 64993840111. The next prime is 64993840147. The reversal of 64993840128 is 82104839946.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 413973426 + ... + 413973582.

Almost surely, 2^64993840128 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 64993840128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120221325312).

64993840128 is an abundant number, since it is smaller than the sum of its proper divisors (175448810496).

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

64993840128 is a wasteful number, since it uses less digits than its factorization.

64993840128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 223 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The spelling of 64993840128 in words is "sixty-four billion, nine hundred ninety-three million, eight hundred forty thousand, one hundred twenty-eight".