643211689 has 8 divisors (see below), whose sum is σ = 647837568. Its totient is φ = 638595360.

The previous prime is 643211651. The next prime is 643211717. The reversal of 643211689 is 986112346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643211689 - 2¹³ = 643203497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643217689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181444 + ... + 184954.

It is an arithmetic number, because the mean of its divisors is an integer number (80979696).

Almost surely, 2^643211689 is an apocalyptic number.

It is an amenable number.

643211689 is a deficient number, since it is larger than the sum of its proper divisors (4625879).

643211689 is a wasteful number, since it uses less digits than its factorization.

643211689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4775.

The product of its digits is 62208, while the sum is 40.

The square root of 643211689 is about 25361.6184223326. The cubic root of 643211689 is about 863.2130076670.

The spelling of 643211689 in words is "six hundred forty-three million, two hundred eleven thousand, six hundred eighty-nine".