643330565 has 16 divisors (see below), whose sum is σ = 779630592. Its totient is φ = 509592384.

The previous prime is 643330559. The next prime is 643330573. The reversal of 643330565 is 565033346.

It is a cyclic number.

It is not a de Polignac number, because 643330565 - 2¹⁴ = 643314181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 575387 + ... + 576503.

It is an arithmetic number, because the mean of its divisors is an integer number (48726912).

Almost surely, 2^643330565 is an apocalyptic number.

It is an amenable number.

643330565 is a deficient number, since it is larger than the sum of its proper divisors (136300027).

643330565 is a wasteful number, since it uses less digits than its factorization.

643330565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2156.

The product of its (nonzero) digits is 97200, while the sum is 35.

The square root of 643330565 is about 25363.9619342089. The cubic root of 643330565 is about 863.2661830007.

The spelling of 643330565 in words is "six hundred forty-three million, three hundred thirty thousand, five hundred sixty-five".