643788138240 has 1152 divisors, whose sum is σ = 2534232960000. Its totient is φ = 153790119936.

The previous prime is 643788138221. The next prime is 643788138241. The reversal of 643788138240 is 42831887346.

643788138240 is a `hidden beast` number, since 6 + 437 + 88 + 13 + 82 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643788138241) 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 127 ways as a sum of consecutive naturals, for example, 3949620399 + ... + 3949620561.

It is an arithmetic number, because the mean of its divisors is an integer number (2199855000).

Almost surely, 2^643788138240 is an apocalyptic number.

643788138240 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 643788138240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1267116480000).

643788138240 is an abundant number, since it is smaller than the sum of its proper divisors (1890444821760).

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

643788138240 is a wasteful number, since it uses less digits than its factorization.

643788138240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 54.

The spelling of 643788138240 in words is "six hundred forty-three billion, seven hundred eighty-eight million, one hundred thirty-eight thousand, two hundred forty".