643161104 has 10 divisors (see below), whose sum is σ = 1246124670. Its totient is φ = 321580544.

The previous prime is 643161067. The next prime is 643161109. The reversal of 643161104 is 401161346.

It can be written as a sum of positive squares in only one way, i.e., 642521104 + 640000 = 25348^2 + 800^2 .

It is not an unprimeable number, because it can be changed into a prime (643161109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20098769 + ... + 20098800.

It is an arithmetic number, because the mean of its divisors is an integer number (124612467).

Almost surely, 2^643161104 is an apocalyptic number.

It is an amenable number.

643161104 is a deficient number, since it is larger than the sum of its proper divisors (602963566).

643161104 is a wasteful number, since it uses less digits than its factorization.

643161104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40197577 (or 40197571 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 643161104 is about 25360.6211280402. The cubic root of 643161104 is about 863.1903781163.

The spelling of 643161104 in words is "six hundred forty-three million, one hundred sixty-one thousand, one hundred four".