209159421 has 4 divisors (see below), whose sum is σ = 278879232. Its totient is φ = 139439612.

The previous prime is 209159399. The next prime is 209159441. The reversal of 209159421 is 124951902.

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 209159421 - 2⁹ = 209158909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209159441) 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, 34859901 + ... + 34859906.

It is an arithmetic number, because the mean of its divisors is an integer number (69719808).

Almost surely, 2^209159421 is an apocalyptic number.

It is an amenable number.

209159421 is a deficient number, since it is larger than the sum of its proper divisors (69719811).

209159421 is an equidigital number, since it uses as much as digits as its factorization.

209159421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69719810.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 209159421 is about 14462.3449343459. The cubic root of 209159421 is about 593.5980655607.

The spelling of 209159421 in words is "two hundred nine million, one hundred fifty-nine thousand, four hundred twenty-one".