204115421 has 4 divisors (see below), whose sum is σ = 209632092. Its totient is φ = 198598752.

The previous prime is 204115411. The next prime is 204115441. The reversal of 204115421 is 124511402.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 72760900 + 131354521 = 8530^2 + 11461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204115421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204115393 and 204115402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204115411) 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, 2758280 + ... + 2758353.

It is an arithmetic number, because the mean of its divisors is an integer number (52408023).

Almost surely, 2^204115421 is an apocalyptic number.

It is an amenable number.

204115421 is a deficient number, since it is larger than the sum of its proper divisors (5516671).

204115421 is an equidigital number, since it uses as much as digits as its factorization.

204115421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5516670.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 204115421 is about 14286.8968289128. The cubic root of 204115421 is about 588.7875330342.

Adding to 204115421 its reverse (124511402), we get a palindrome (328626823).

The spelling of 204115421 in words is "two hundred four million, one hundred fifteen thousand, four hundred twenty-one".