643672958889 has 16 divisors (see below), whose sum is σ = 871307553600. Its totient is φ = 422594678016.

The previous prime is 643672958879. The next prime is 643672958899. The reversal of 643672958889 is 988859276346.

It is an interprime number because it is at equal distance from previous prime (643672958879) and next prime (643672958899).

It is not a de Polignac number, because 643672958889 - 2⁵ = 643672958857 is a prime.

It is a super-2 number, since 2×643672958889² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643672958889.

It is not an unprimeable number, because it can be changed into a prime (643672958879) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2085684 + ... + 2374325.

It is an arithmetic number, because the mean of its divisors is an integer number (54456722100).

Almost surely, 2^643672958889 is an apocalyptic number.

It is an amenable number.

643672958889 is a deficient number, since it is larger than the sum of its proper divisors (227634594711).

643672958889 is a wasteful number, since it uses less digits than its factorization.

643672958889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4460744.

The product of its digits is 1254113280, while the sum is 75.

The spelling of 643672958889 in words is "six hundred forty-three billion, six hundred seventy-two million, nine hundred fifty-eight thousand, eight hundred eighty-nine".