643635339 has 16 divisors (see below), whose sum is σ = 888719904. Its totient is φ = 414086400.

The previous prime is 643635331. The next prime is 643635341. The reversal of 643635339 is 933536346.

It is a happy number.

It is not a de Polignac number, because 643635339 - 2³ = 643635331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643635339.

It is not an unprimeable number, because it can be changed into a prime (643635331) 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, 23482 + ... + 42879.

It is an arithmetic number, because the mean of its divisors is an integer number (55544994).

Almost surely, 2^643635339 is an apocalyptic number.

643635339 is a deficient number, since it is larger than the sum of its proper divisors (245084565).

643635339 is a wasteful number, since it uses less digits than its factorization.

643635339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66478.

The product of its digits is 524880, while the sum is 42.

The square root of 643635339 is about 25369.9692352987. The cubic root of 643635339 is about 863.4024838727.

The spelling of 643635339 in words is "six hundred forty-three million, six hundred thirty-five thousand, three hundred thirty-nine".