643144109 has 2 divisors, whose sum is σ = 643144110. Its totient is φ = 643144108.

The previous prime is 643144097. The next prime is 643144157. The reversal of 643144109 is 901441346.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 484132009 + 159012100 = 22003^2 + 12610^2 .

It is a cyclic number.

It is not a de Polignac number, because 643144109 - 2¹² = 643140013 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643140109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321572054 + 321572055.

It is an arithmetic number, because the mean of its divisors is an integer number (321572055).

Almost surely, 2^643144109 is an apocalyptic number.

It is an amenable number.

643144109 is a deficient number, since it is larger than the sum of its proper divisors (1).

643144109 is an equidigital number, since it uses as much as digits as its factorization.

643144109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 643144109 is about 25360.2860591122. The cubic root of 643144109 is about 863.1827750188.

The spelling of 643144109 in words is "six hundred forty-three million, one hundred forty-four thousand, one hundred nine".