205312500 has 144 divisors (see below), whose sum is σ = 657615504. Its totient is φ = 54000000.

The previous prime is 205312493. The next prime is 205312517. The reversal of 205312500 is 5213502.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 164403684 + 40908816 = 12822^2 + 6396^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2812464 + ... + 2812536.

Almost surely, 2^205312500 is an apocalyptic number.

205312500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205312500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328807752).

205312500 is an abundant number, since it is smaller than the sum of its proper divisors (452303004).

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

205312500 is an frugal number, since it uses more digits than its factorization.

205312500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 205312500 is about 14328.7298809071. The cubic root of 205312500 is about 589.9363141064.

The spelling of 205312500 in words is "two hundred five million, three hundred twelve thousand, five hundred".