210641009 has 2 divisors, whose sum is σ = 210641010. Its totient is φ = 210641008.

The previous prime is 210641003. The next prime is 210641023. The reversal of 210641009 is 900146012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159946609 + 50694400 = 12647^2 + 7120^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210641009 is a prime.

It is not a weakly prime, because it can be changed into another prime (210641003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105320504 + 105320505.

It is an arithmetic number, because the mean of its divisors is an integer number (105320505).

Almost surely, 2^210641009 is an apocalyptic number.

It is an amenable number.

210641009 is a deficient number, since it is larger than the sum of its proper divisors (1).

210641009 is an equidigital number, since it uses as much as digits as its factorization.

210641009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 210641009 is about 14513.4768060586. The cubic root of 210641009 is about 594.9963599335.

The spelling of 210641009 in words is "two hundred ten million, six hundred forty-one thousand, nine".