205121500 has 24 divisors (see below), whose sum is σ = 447986448. Its totient is φ = 82048400.

The previous prime is 205121479. The next prime is 205121509. The reversal of 205121500 is 5121502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205121509) 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 7 ways as a sum of consecutive naturals, for example, 204622 + ... + 205621.

It is an arithmetic number, because the mean of its divisors is an integer number (18666102).

Almost surely, 2^205121500 is an apocalyptic number.

205121500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205121500 is an abundant number, since it is smaller than the sum of its proper divisors (242864948).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205121500 is a wasteful number, since it uses less digits than its factorization.

205121500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410262 (or 410250 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 205121500 is about 14322.0633988263. The cubic root of 205121500 is about 589.7533202230.

The spelling of 205121500 in words is "two hundred five million, one hundred twenty-one thousand, five hundred".