643606262237 has 2 divisors, whose sum is σ = 643606262238. Its totient is φ = 643606262236.

The previous prime is 643606262197. The next prime is 643606262239. The reversal of 643606262237 is 732262606346.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 607119914041 + 36486348196 = 779179^2 + 191014^2 .

It is a cyclic number.

It is not a de Polignac number, because 643606262237 - 2²⁰ = 643605213661 is a prime.

Together with 643606262239, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 643606262191 and 643606262200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643606262239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321803131118 + 321803131119.

It is an arithmetic number, because the mean of its divisors is an integer number (321803131119).

Almost surely, 2^643606262237 is an apocalyptic number.

It is an amenable number.

643606262237 is a deficient number, since it is larger than the sum of its proper divisors (1).

643606262237 is an equidigital number, since it uses as much as digits as its factorization.

643606262237 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 47.

The spelling of 643606262237 in words is "six hundred forty-three billion, six hundred six million, two hundred sixty-two thousand, two hundred thirty-seven".