643938035 has 16 divisors (see below), whose sum is σ = 832702080. Its totient is φ = 475217280.

The previous prime is 643938013. The next prime is 643938049. The reversal of 643938035 is 530839346.

It is not a de Polignac number, because 643938035 - 2¹⁶ = 643872499 is a prime.

It is a super-2 number, since 2×643938035² = 829312385839322450, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643937983 and 643938001.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 171761 + ... + 175469.

It is an arithmetic number, because the mean of its divisors is an integer number (52043880).

Almost surely, 2^643938035 is an apocalyptic number.

643938035 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

643938035 is a deficient number, since it is larger than the sum of its proper divisors (188764045).

643938035 is a wasteful number, since it uses less digits than its factorization.

643938035 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6398.

The product of its (nonzero) digits is 233280, while the sum is 41.

The square root of 643938035 is about 25375.9341699966. The cubic root of 643938035 is about 863.5378128409.

The spelling of 643938035 in words is "six hundred forty-three million, nine hundred thirty-eight thousand, thirty-five".