643669173 has 80 divisors (see below), whose sum is σ = 1137438720. Its totient is φ = 355168800.

The previous prime is 643669171. The next prime is 643669177. The reversal of 643669173 is 371966346.

It is not a de Polignac number, because 643669173 - 2¹ = 643669171 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643669171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2375028 + ... + 2375298.

It is an arithmetic number, because the mean of its divisors is an integer number (14217984).

Almost surely, 2^643669173 is an apocalyptic number.

643669173 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

643669173 is a deficient number, since it is larger than the sum of its proper divisors (493769547).

643669173 is a wasteful number, since it uses less digits than its factorization.

643669173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420 (or 411 counting only the distinct ones).

The product of its digits is 489888, while the sum is 45.

The square root of 643669173 is about 25370.6360385387. The cubic root of 643669173 is about 863.4176124432.

The spelling of 643669173 in words is "six hundred forty-three million, six hundred sixty-nine thousand, one hundred seventy-three".