64880857840 has 80 divisors (see below), whose sum is σ = 156370214880. Its totient is φ = 25005962240.

The previous prime is 64880857817. The next prime is 64880857861. The reversal of 64880857840 is 4875808846.

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

It is a Harshad number since it is a multiple of its sum of digits (58).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1110642 + ... + 1167598.

It is an arithmetic number, because the mean of its divisors is an integer number (1954627686).

Almost surely, 2^64880857840 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 64880857840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78185107440).

64880857840 is an abundant number, since it is smaller than the sum of its proper divisors (91489357040).

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

64880857840 is a wasteful number, since it uses less digits than its factorization.

64880857840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57490 (or 57484 counting only the distinct ones).

The product of its (nonzero) digits is 13762560, while the sum is 58.

The spelling of 64880857840 in words is "sixty-four billion, eight hundred eighty million, eight hundred fifty-seven thousand, eight hundred forty".