643661253325229 has 2 divisors, whose sum is σ = 643661253325230. Its totient is φ = 643661253325228.

The previous prime is 643661253325147. The next prime is 643661253325241. The reversal of 643661253325229 is 922523352166346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490708002724900 + 152953250600329 = 22151930^2 + 12367427^2 .

It is a cyclic number.

It is not a de Polignac number, because 643661253325229 - 2²⁴ = 643661236548013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643661253325729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321830626662614 + 321830626662615.

It is an arithmetic number, because the mean of its divisors is an integer number (321830626662615).

Almost surely, 2^{643661253325229} is an apocalyptic number.

It is an amenable number.

643661253325229 is a deficient number, since it is larger than the sum of its proper divisors (1).

643661253325229 is an equidigital number, since it uses as much as digits as its factorization.

643661253325229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 83980800, while the sum is 59.

The spelling of 643661253325229 in words is "six hundred forty-three trillion, six hundred sixty-one billion, two hundred fifty-three million, three hundred twenty-five thousand, two hundred twenty-nine".