643876245 has 24 divisors (see below), whose sum is σ = 1126490976. Its totient is φ = 340188768.

The previous prime is 643876229. The next prime is 643876249. The reversal of 643876245 is 542678346.

It is not a de Polignac number, because 643876245 - 2⁴ = 643876229 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 643876245.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643876249) 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 23 ways as a sum of consecutive naturals, for example, 62047 + ... + 71676.

It is an arithmetic number, because the mean of its divisors is an integer number (46937124).

Almost surely, 2^643876245 is an apocalyptic number.

It is an amenable number.

643876245 is a deficient number, since it is larger than the sum of its proper divisors (482614731).

643876245 is a wasteful number, since it uses less digits than its factorization.

643876245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133841 (or 133838 counting only the distinct ones).

The product of its digits is 967680, while the sum is 45.

The square root of 643876245 is about 25374.7166486643. The cubic root of 643876245 is about 863.5101912866.

The spelling of 643876245 in words is "six hundred forty-three million, eight hundred seventy-six thousand, two hundred forty-five".