64421636328 has 144 divisors (see below), whose sum is σ = 203056289280. Its totient is φ = 18397544256.

The previous prime is 64421636317. The next prime is 64421636351. The reversal of 64421636328 is 82363612446.

64421636328 is a `hidden beast` number, since 6 + 4 + 4 + 2 + 1 + 6 + 3 + 632 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13993275 + ... + 13997877.

It is an arithmetic number, because the mean of its divisors is an integer number (1410113120).

Almost surely, 2^64421636328 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 64421636328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101528144640).

64421636328 is an abundant number, since it is smaller than the sum of its proper divisors (138634652952).

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

64421636328 is a wasteful number, since it uses less digits than its factorization.

64421636328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8596 (or 8582 counting only the distinct ones).

The product of its digits is 995328, while the sum is 45.

The spelling of 64421636328 in words is "sixty-four billion, four hundred twenty-one million, six hundred thirty-six thousand, three hundred twenty-eight".