643180321 has 9 divisors (see below), whose sum is σ = 748395921. Its totient is φ = 551145252.

The previous prime is 643180319. The next prime is 643180327. The reversal of 643180321 is 123081346.

The square root of 643180321 is 25361.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 643180321 - 2¹ = 643180319 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643180321.

It is not an unprimeable number, because it can be changed into a prime (643180327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 175716 + ... + 179338.

Almost surely, 2^643180321 is an apocalyptic number.

643180321 is the 25361-st square number.

643180321 is the 12681-st centered octagonal number.

It is an amenable number.

643180321 is a deficient number, since it is larger than the sum of its proper divisors (105215600).

643180321 is an frugal number, since it uses more digits than its factorization.

643180321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7260 (or 3630 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The cubic root of 643180321 is about 863.1989751143.

The spelling of 643180321 in words is "six hundred forty-three million, one hundred eighty thousand, three hundred twenty-one".