643541564 has 12 divisors (see below), whose sum is σ = 1175163024. Its totient is φ = 307780704.

The previous prime is 643541557. The next prime is 643541567. The reversal of 643541564 is 465145346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643541567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3497417 + ... + 3497600.

It is an arithmetic number, because the mean of its divisors is an integer number (97930252).

Almost surely, 2^643541564 is an apocalyptic number.

It is an amenable number.

643541564 is a deficient number, since it is larger than the sum of its proper divisors (531621460).

643541564 is a wasteful number, since it uses less digits than its factorization.

643541564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6995044 (or 6995042 counting only the distinct ones).

The product of its digits is 172800, while the sum is 38.

The square root of 643541564 is about 25368.1210183175. The cubic root of 643541564 is about 863.3605504489.

The spelling of 643541564 in words is "six hundred forty-three million, five hundred forty-one thousand, five hundred sixty-four".