643316929 has 4 divisors (see below), whose sum is σ = 664069120. Its totient is φ = 622564740.

The previous prime is 643316917. The next prime is 643316951. The reversal of 643316929 is 929613346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643316929 - 2¹⁷ = 643185857 is a prime.

It is a super-2 number, since 2×643316929² = 827713342275982082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643316909) 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 3 ways as a sum of consecutive naturals, for example, 10376049 + ... + 10376110.

It is an arithmetic number, because the mean of its divisors is an integer number (166017280).

Almost surely, 2^643316929 is an apocalyptic number.

It is an amenable number.

643316929 is a deficient number, since it is larger than the sum of its proper divisors (20752191).

643316929 is a wasteful number, since it uses less digits than its factorization.

643316929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20752190.

The product of its digits is 209952, while the sum is 43.

The square root of 643316929 is about 25363.6931261991. The cubic root of 643316929 is about 863.2600837098.

The spelling of 643316929 in words is "six hundred forty-three million, three hundred sixteen thousand, nine hundred twenty-nine".