64139821056 has 320 divisors, whose sum is σ = 199313136000. Its totient is φ = 20346568704.

The previous prime is 64139820959. The next prime is 64139821063. The reversal of 64139821056 is 65012893146.

64139821056 is a `hidden beast` number, since 6 + 41 + 398 + 210 + 5 + 6 = 666.

It is a super-2 number, since 2×64139821056² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 325582750 + ... + 325582946.

It is an arithmetic number, because the mean of its divisors is an integer number (622853550).

Almost surely, 2^64139821056 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 64139821056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99656568000).

64139821056 is an abundant number, since it is smaller than the sum of its proper divisors (135173314944).

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

64139821056 is an frugal number, since it uses more digits than its factorization.

64139821056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267 (or 225 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 64139821056 in words is "sixty-four billion, one hundred thirty-nine million, eight hundred twenty-one thousand, fifty-six".