204401009 has 2 divisors, whose sum is σ = 204401010. Its totient is φ = 204401008.

The previous prime is 204400997. The next prime is 204401033. The reversal of 204401009 is 900104402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 202066225 + 2334784 = 14215^2 + 1528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204401009 is a prime.

It is not a weakly prime, because it can be changed into another prime (204401909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102200504 + 102200505.

It is an arithmetic number, because the mean of its divisors is an integer number (102200505).

Almost surely, 2^204401009 is an apocalyptic number.

It is an amenable number.

204401009 is a deficient number, since it is larger than the sum of its proper divisors (1).

204401009 is an equidigital number, since it uses as much as digits as its factorization.

204401009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 204401009 is about 14296.8880879722. Note that the first 3 decimals coincide. The cubic root of 204401009 is about 589.0620056691.

The spelling of 204401009 in words is "two hundred four million, four hundred one thousand, nine".