209401 has 2 divisors, whose sum is σ = 209402. Its totient is φ = 209400.

The previous prime is 209393. The next prime is 209431. The reversal of 209401 is 104902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133225 + 76176 = 365^2 + 276^2 .

It is a cyclic number.

It is not a de Polignac number, because 209401 - 2³ = 209393 is a prime.

It is not a weakly prime, because it can be changed into another prime (209431) 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, 104700 + 104701.

It is an arithmetic number, because the mean of its divisors is an integer number (104701).

2²⁰⁹⁴⁰¹ is an apocalyptic number.

It is an amenable number.

209401 is a deficient number, since it is larger than the sum of its proper divisors (1).

209401 is an equidigital number, since it uses as much as digits as its factorization.

209401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 209401 is about 457.6035401961. The cubic root of 209401 is about 59.3826512762.

The spelling of 209401 in words is "two hundred nine thousand, four hundred one".