643290577 has 4 divisors (see below), whose sum is σ = 643503796. Its totient is φ = 643077360.

The previous prime is 643290559. The next prime is 643290607. The reversal of 643290577 is 775092346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 480881041 + 162409536 = 21929^2 + 12744^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643290577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643290677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102018 + ... + 108139.

It is an arithmetic number, because the mean of its divisors is an integer number (160875949).

Almost surely, 2^643290577 is an apocalyptic number.

It is an amenable number.

643290577 is a deficient number, since it is larger than the sum of its proper divisors (213219).

643290577 is a wasteful number, since it uses less digits than its factorization.

643290577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213218.

The product of its (nonzero) digits is 317520, while the sum is 43.

The square root of 643290577 is about 25363.1736381708. The cubic root of 643290577 is about 863.2482963935.

The spelling of 643290577 in words is "six hundred forty-three million, two hundred ninety thousand, five hundred seventy-seven".