643400313 has 16 divisors (see below), whose sum is σ = 877988160. Its totient is φ = 418989824.

The previous prime is 643400311. The next prime is 643400339. The reversal of 643400313 is 313004346.

It is a cyclic number.

It is not a de Polignac number, because 643400313 - 2¹ = 643400311 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643400311) 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, 7645 + ... + 36677.

It is an arithmetic number, because the mean of its divisors is an integer number (54874260).

Almost surely, 2^643400313 is an apocalyptic number.

It is an amenable number.

643400313 is a deficient number, since it is larger than the sum of its proper divisors (234587847).

643400313 is a wasteful number, since it uses less digits than its factorization.

643400313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29208.

The product of its (nonzero) digits is 2592, while the sum is 24.

The square root of 643400313 is about 25365.3368398687. The cubic root of 643400313 is about 863.2973794634.

Adding to 643400313 its reverse (313004346), we get a palindrome (956404659).

The spelling of 643400313 in words is "six hundred forty-three million, four hundred thousand, three hundred thirteen".