643499733 has 16 divisors (see below), whose sum is σ = 907712000. Its totient is φ = 404371440.

The previous prime is 643499699. The next prime is 643499743. The reversal of 643499733 is 337994346.

643499733 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643499733 - 2¹² = 643495637 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 (643499743) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17023 + ... + 39708.

It is an arithmetic number, because the mean of its divisors is an integer number (56732000).

Almost surely, 2^643499733 is an apocalyptic number.

It is an amenable number.

643499733 is a deficient number, since it is larger than the sum of its proper divisors (264212267).

643499733 is a wasteful number, since it uses less digits than its factorization.

643499733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56952.

The product of its digits is 1469664, while the sum is 48.

The square root of 643499733 is about 25367.2965252508. The cubic root of 643499733 is about 863.3418435413.

The spelling of 643499733 in words is "six hundred forty-three million, four hundred ninety-nine thousand, seven hundred thirty-three".