643421513 has 8 divisors (see below), whose sum is σ = 752440128. Its totient is φ = 538678224.

The previous prime is 643421507. The next prime is 643421539. The reversal of 643421513 is 315124346.

643421513 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 not a de Polignac number, because 643421513 - 2⁸ = 643421257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643421543) 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, 1068506 + ... + 1069107.

It is an arithmetic number, because the mean of its divisors is an integer number (94055016).

Almost surely, 2^643421513 is an apocalyptic number.

It is an amenable number.

643421513 is a deficient number, since it is larger than the sum of its proper divisors (109018615).

643421513 is a wasteful number, since it uses less digits than its factorization.

643421513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2137663.

The product of its digits is 8640, while the sum is 29.

The square root of 643421513 is about 25365.7547295561. The cubic root of 643421513 is about 863.3068612241.

Adding to 643421513 its reverse (315124346), we get a palindrome (958545859).

The spelling of 643421513 in words is "six hundred forty-three million, four hundred twenty-one thousand, five hundred thirteen".