641888000009 has 2 divisors, whose sum is σ = 641888000010. Its totient is φ = 641888000008.

The previous prime is 641887999981. The next prime is 641888000011. The reversal of 641888000009 is 900000888146.

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., 591084192400 + 50803807609 = 768820^2 + 225397^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641888000009 is a prime.

Together with 641888000011, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (641888002009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320944000004 + 320944000005.

It is an arithmetic number, because the mean of its divisors is an integer number (320944000005).

Almost surely, 2^641888000009 is an apocalyptic number.

It is an amenable number.

641888000009 is a deficient number, since it is larger than the sum of its proper divisors (1).

641888000009 is an equidigital number, since it uses as much as digits as its factorization.

641888000009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 44.

The spelling of 641888000009 in words is "six hundred forty-one billion, eight hundred eighty-eight million, nine", and thus it is an aban number.