210020209 has 4 divisors (see below), whose sum is σ = 240023104. Its totient is φ = 180017316.

The previous prime is 210020203. The next prime is 210020221. The reversal of 210020209 is 902020012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210020209 - 2¹⁹ = 209495921 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210020192 and 210020201.

It is not an unprimeable number, because it can be changed into a prime (210020203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15001437 + ... + 15001450.

It is an arithmetic number, because the mean of its divisors is an integer number (60005776).

Almost surely, 2^210020209 is an apocalyptic number.

It is an amenable number.

210020209 is a deficient number, since it is larger than the sum of its proper divisors (30002895).

210020209 is an equidigital number, since it uses as much as digits as its factorization.

210020209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30002894.

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

The square root of 210020209 is about 14492.0740061594. The cubic root of 210020209 is about 594.4112614455.

The spelling of 210020209 in words is "two hundred ten million, twenty thousand, two hundred nine".