643989346 has 48 divisors (see below), whose sum is σ = 1306855872. Its totient is φ = 231596640.

The previous prime is 643989343. The next prime is 643989389.

643989346 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 643989293 and 643989302.

It is not an unprimeable number, because it can be changed into a prime (643989343) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7401 + ... + 36643.

It is an arithmetic number, because the mean of its divisors is an integer number (27226164).

Almost surely, 2^643989346 is an apocalyptic number.

643989346 is an abundant number, since it is smaller than the sum of its proper divisors (662866526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643989346 is a wasteful number, since it uses less digits than its factorization.

643989346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29287 (or 29276 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 52.

The square root of 643989346 is about 25376.9451668242. The cubic root of 643989346 is about 863.5607486978.

It can be divided in two parts, 643 and 989346, that added together give a palindrome (989989).

The spelling of 643989346 in words is "six hundred forty-three million, nine hundred eighty-nine thousand, three hundred forty-six".