643527361 has 4 divisors (see below), whose sum is σ = 644598724. Its totient is φ = 642456000.

The previous prime is 643527343. The next prime is 643527377. The reversal of 643527361 is 163725346.

643527361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 554885136 + 88642225 = 23556^2 + 9415^2 .

It is a cyclic number.

It is not a de Polignac number, because 643527361 - 2⁵ = 643527329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643527361.

It is not an unprimeable number, because it can be changed into a prime (643527301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 534780 + ... + 535981.

It is an arithmetic number, because the mean of its divisors is an integer number (161149681).

Almost surely, 2^643527361 is an apocalyptic number.

It is an amenable number.

643527361 is a deficient number, since it is larger than the sum of its proper divisors (1071363).

643527361 is a wasteful number, since it uses less digits than its factorization.

643527361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071362.

The product of its digits is 90720, while the sum is 37.

The square root of 643527361 is about 25367.8410788147. The cubic root of 643527361 is about 863.3541989296.

The spelling of 643527361 in words is "six hundred forty-three million, five hundred twenty-seven thousand, three hundred sixty-one".