643948733 has 8 divisors (see below), whose sum is σ = 673124928. Its totient is φ = 614870784.

The previous prime is 643948727. The next prime is 643948769. The reversal of 643948733 is 337849346.

643948733 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643948733 - 2⁴ = 643948717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643948793) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10991 + ... + 37532.

It is an arithmetic number, because the mean of its divisors is an integer number (84140616).

Almost surely, 2^643948733 is an apocalyptic number.

It is an amenable number.

643948733 is a deficient number, since it is larger than the sum of its proper divisors (29176195).

643948733 is a wasteful number, since it uses less digits than its factorization.

643948733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49123.

The product of its digits is 1306368, while the sum is 47.

The square root of 643948733 is about 25376.1449593905. The cubic root of 643948733 is about 863.5425949141.

The spelling of 643948733 in words is "six hundred forty-three million, nine hundred forty-eight thousand, seven hundred thirty-three".