209343421 has 4 divisors (see below), whose sum is σ = 239249632. Its totient is φ = 179437212.

The previous prime is 209343419. The next prime is 209343427. The reversal of 209343421 is 124343902.

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 209343421 - 2¹ = 209343419 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 209343421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209343427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14953095 + ... + 14953108.

It is an arithmetic number, because the mean of its divisors is an integer number (59812408).

Almost surely, 2^209343421 is an apocalyptic number.

It is an amenable number.

209343421 is a deficient number, since it is larger than the sum of its proper divisors (29906211).

209343421 is an equidigital number, since it uses as much as digits as its factorization.

209343421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29906210.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 209343421 is about 14468.7048832990. The cubic root of 209343421 is about 593.7720796074.

It can be divided in two parts, 209343 and 421, that added together give a square (209764 = 458²).

The spelling of 209343421 in words is "two hundred nine million, three hundred forty-three thousand, four hundred twenty-one".