643902605280 has 1344 divisors, whose sum is σ = 2689017766848. Its totient is φ = 143884615680.

The previous prime is 643902605243. The next prime is 643902605287. The reversal of 643902605280 is 82506209346.

643902605280 is a `hidden beast` number, since 6 + 4 + 39 + 0 + 2 + 605 + 2 + 8 + 0 = 666.

643902605280 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×643902605280² (a number of 24 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) 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 (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643902605287) by changing a digit.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 1156018762 + ... + 1156019318.

It is an arithmetic number, because the mean of its divisors is an integer number (2000757267).

Almost surely, 2^643902605280 is an apocalyptic number.

643902605280 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 643902605280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1344508883424).

643902605280 is an abundant number, since it is smaller than the sum of its proper divisors (2045115161568).

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

643902605280 is a wasteful number, since it uses less digits than its factorization.

643902605280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671 (or 648 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 643902605280 in words is "six hundred forty-three billion, nine hundred two million, six hundred five thousand, two hundred eighty".