64781323992 has 640 divisors, whose sum is σ = 248563814400. Its totient is φ = 15242515200.

The previous prime is 64781323967. The next prime is 64781323993. The reversal of 64781323992 is 29932318746.

64781323992 is a `hidden beast` number, since 6 + 478 + 132 + 39 + 9 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64781323993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 21803067 + ... + 21806037.

It is an arithmetic number, because the mean of its divisors is an integer number (388380960).

Almost surely, 2^64781323992 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 64781323992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124281907200).

64781323992 is an abundant number, since it is smaller than the sum of its proper divisors (183782490408).

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

64781323992 is a wasteful number, since it uses less digits than its factorization.

64781323992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3049 (or 3036 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 54.

The spelling of 64781323992 in words is "sixty-four billion, seven hundred eighty-one million, three hundred twenty-three thousand, nine hundred ninety-two".