64821885856 has 192 divisors, whose sum is σ = 162732810240. Its totient is φ = 24725191680.

The previous prime is 64821885841. The next prime is 64821885881. The reversal of 64821885856 is 65858812846.

It is a junction number, because it is equal to n+sod(n) for n = 64821885794 and 64821885803.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27712335 + ... + 27714673.

It is an arithmetic number, because the mean of its divisors is an integer number (847566720).

Almost surely, 2^64821885856 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 64821885856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81366405120).

64821885856 is an abundant number, since it is smaller than the sum of its proper divisors (97910924384).

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

64821885856 is a wasteful number, since it uses less digits than its factorization.

64821885856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2707 (or 2699 counting only the distinct ones).

The product of its digits is 29491200, while the sum is 61.

The spelling of 64821885856 in words is "sixty-four billion, eight hundred twenty-one million, eight hundred eighty-five thousand, eight hundred fifty-six".