64391989120 has 128 divisors (see below), whose sum is σ = 157940798400. Its totient is φ = 25088901120.

The previous prime is 64391989097. The next prime is 64391989141. The reversal of 64391989120 is 2198919346.

It is a tau number, because it is divible by the number of its divisors (128).

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, 20911741 + ... + 20914819.

Almost surely, 2^64391989120 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 64391989120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78970399200).

64391989120 is an abundant number, since it is smaller than the sum of its proper divisors (93548809280).

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

64391989120 is a wasteful number, since it uses less digits than its factorization.

64391989120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3936 (or 3924 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 52.

The spelling of 64391989120 in words is "sixty-four billion, three hundred ninety-one million, nine hundred eighty-nine thousand, one hundred twenty".