641888002009 has 2 divisors, whose sum is σ = 641888002010. Its totient is φ = 641888002008.

The previous prime is 641888001929. The next prime is 641888002027. The reversal of 641888002009 is 900200888146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 641729166400 + 158835609 = 801080^2 + 12603^2 .

It is a cyclic number.

It is not a de Polignac number, because 641888002009 - 2¹⁷ = 641887870937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 641888002009.

It is not a weakly prime, because it can be changed into another prime (641888002109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320944001004 + 320944001005.

It is an arithmetic number, because the mean of its divisors is an integer number (320944001005).

Almost surely, 2^641888002009 is an apocalyptic number.

It is an amenable number.

641888002009 is a deficient number, since it is larger than the sum of its proper divisors (1).

641888002009 is an equidigital number, since it uses as much as digits as its factorization.

641888002009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 221184, while the sum is 46.

The spelling of 641888002009 in words is "six hundred forty-one billion, eight hundred eighty-eight million, two thousand, nine".