204630551 has 4 divisors (see below), whose sum is σ = 215400600. Its totient is φ = 193860504.

The previous prime is 204630541. The next prime is 204630553. The reversal of 204630551 is 155036402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155036402 = 2 ⋅77518201.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204630551 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 204630551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204630553) 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, 5384996 + ... + 5385033.

It is an arithmetic number, because the mean of its divisors is an integer number (53850150).

Almost surely, 2^204630551 is an apocalyptic number.

204630551 is a deficient number, since it is larger than the sum of its proper divisors (10770049).

204630551 is a wasteful number, since it uses less digits than its factorization.

204630551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10770048.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 204630551 is about 14304.9135264775. The cubic root of 204630551 is about 589.2824284023.

Adding to 204630551 its reverse (155036402), we get a palindrome (359666953).

The spelling of 204630551 in words is "two hundred four million, six hundred thirty thousand, five hundred fifty-one".