643484689 has 3 divisors (see below), whose sum is σ = 643510057. Its totient is φ = 643459322.

The previous prime is 643484671. The next prime is 643484789. The reversal of 643484689 is 986484346.

It is a happy number.

The square root of 643484689 is 25367.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 643484689 - 2¹⁷ = 643353617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643484789) 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 2 ways as a sum of consecutive naturals, for example, 12684 + ... + 38050.

Almost surely, 2^643484689 is an apocalyptic number.

643484689 is the 25367-th square number.

643484689 is the 12684-th centered octagonal number.

It is an amenable number.

643484689 is a deficient number, since it is larger than the sum of its proper divisors (25368).

643484689 is an frugal number, since it uses more digits than its factorization.

643484689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50734 (or 25367 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 52.

The cubic root of 643484689 is about 863.3351156360.

The spelling of 643484689 in words is "six hundred forty-three million, four hundred eighty-four thousand, six hundred eighty-nine".