64631623680 has 936 divisors, whose sum is σ = 257299558152. Its totient is φ = 15479341056.

The previous prime is 64631623673. The next prime is 64631623711. The reversal of 64631623680 is 8632613646.

64631623680 is a `hidden beast` number, since 6 + 4 + 631 + 6 + 2 + 3 + 6 + 8 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7766544384 + 56865079296 = 88128^2 + 238464^2 .

It is a tau number, because it is divible by the number of its divisors (936).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 71 ways as a sum of consecutive naturals, for example, 1746800622 + ... + 1746800658.

Almost surely, 2^64631623680 is an apocalyptic number.

64631623680 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 64631623680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128649779076).

64631623680 is an abundant number, since it is smaller than the sum of its proper divisors (192667934472).

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

64631623680 is an frugal number, since it uses more digits than its factorization.

64631623680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

The spelling of 64631623680 in words is "sixty-four billion, six hundred thirty-one million, six hundred twenty-three thousand, six hundred eighty".