643635341 has 2 divisors, whose sum is σ = 643635342. Its totient is φ = 643635340.

The previous prime is 643635331. The next prime is 643635353. The reversal of 643635341 is 143536346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 527620900 + 116014441 = 22970^2 + 10771^2 .

It is a cyclic number.

It is not a de Polignac number, because 643635341 - 2²² = 639441037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643635331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321817670 + 321817671.

It is an arithmetic number, because the mean of its divisors is an integer number (321817671).

Almost surely, 2^643635341 is an apocalyptic number.

It is an amenable number.

643635341 is a deficient number, since it is larger than the sum of its proper divisors (1).

643635341 is an equidigital number, since it uses as much as digits as its factorization.

643635341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 35.

The square root of 643635341 is about 25369.9692747153. The cubic root of 643635341 is about 863.4024847670.

The spelling of 643635341 in words is "six hundred forty-three million, six hundred thirty-five thousand, three hundred forty-one".