643144061 has 6 divisors (see below), whose sum is σ = 748147230. Its totient is φ = 551266296.

The previous prime is 643144043. The next prime is 643144079. The reversal of 643144061 is 160441346.

It is an interprime number because it is at equal distance from previous prime (643144043) and next prime (643144079).

It can be written as a sum of positive squares in only one way, i.e., 530380900 + 112763161 = 23030^2 + 10619^2 .

It is not a de Polignac number, because 643144061 - 2⁶ = 643143997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643144001) 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 5 ways as a sum of consecutive naturals, for example, 6562646 + ... + 6562743.

It is an arithmetic number, because the mean of its divisors is an integer number (124691205).

Almost surely, 2^643144061 is an apocalyptic number.

It is an amenable number.

643144061 is a deficient number, since it is larger than the sum of its proper divisors (105003169).

643144061 is a wasteful number, since it uses less digits than its factorization.

643144061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13125403 (or 13125396 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 643144061 is about 25360.2851127506. The cubic root of 643144061 is about 863.1827535447.

The spelling of 643144061 in words is "six hundred forty-three million, one hundred forty-four thousand, sixty-one".