643427920128 has 576 divisors, whose sum is σ = 2111646523392. Its totient is φ = 169763143680.

The previous prime is 643427920127. The next prime is 643427920229. The reversal of 643427920128 is 821029724346.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (643427920123) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2055680100 + ... + 2055680412.

It is an arithmetic number, because the mean of its divisors is an integer number (3666052992).

Almost surely, 2^643427920128 is an apocalyptic number.

643427920128 is a gapful number since it is divisible by the number (68) 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 643427920128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1055823261696).

643427920128 is an abundant number, since it is smaller than the sum of its proper divisors (1468218603264).

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

643427920128 is a wasteful number, since it uses less digits than its factorization.

643427920128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710 (or 696 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 48.

The spelling of 643427920128 in words is "six hundred forty-three billion, four hundred twenty-seven million, nine hundred twenty thousand, one hundred twenty-eight".