64722320640 has 432 divisors, whose sum is σ = 233370184320. Its totient is φ = 16540876800.

The previous prime is 64722320617. The next prime is 64722320647. The reversal of 64722320640 is 4602322746.

64722320640 is a `hidden beast` number, since 6 + 4 + 7 + 2 + 2 + 3 + 2 + 0 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 64722320595 and 64722320604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64722320647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50445439 + ... + 50446721.

It is an arithmetic number, because the mean of its divisors is an integer number (540208760).

Almost surely, 2^64722320640 is an apocalyptic number.

64722320640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64722320640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116685092160).

64722320640 is an abundant number, since it is smaller than the sum of its proper divisors (168647863680).

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

64722320640 is a wasteful number, since it uses less digits than its factorization.

64722320640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1490 (or 1473 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 36.

The spelling of 64722320640 in words is "sixty-four billion, seven hundred twenty-two million, three hundred twenty thousand, six hundred forty".