204399989 has 4 divisors (see below), whose sum is σ = 204479520. Its totient is φ = 204320460.

The previous prime is 204399973. The next prime is 204399997. The reversal of 204399989 is 989993402.

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 204399989 - 2⁴ = 204399973 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 204399989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204399389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35777 + ... + 41094.

It is an arithmetic number, because the mean of its divisors is an integer number (51119880).

Almost surely, 2^204399989 is an apocalyptic number.

It is an amenable number.

204399989 is a deficient number, since it is larger than the sum of its proper divisors (79531).

204399989 is an equidigital number, since it uses as much as digits as its factorization.

204399989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79530.

The product of its (nonzero) digits is 1259712, while the sum is 53.

The square root of 204399989 is about 14296.8524158292. The cubic root of 204399989 is about 589.0610258236.

The spelling of 204399989 in words is "two hundred four million, three hundred ninety-nine thousand, nine hundred eighty-nine".