205704720 has 120 divisors (see below), whose sum is σ = 743999256. Its totient is φ = 50632704.

The previous prime is 205704689. The next prime is 205704727. The reversal of 205704720 is 27407502.

205704720 is a `hidden beast` number, since 20 + 570 + 4 + 72 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2471184 + 203233536 = 1572^2 + 14256^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is not an unprimeable number, because it can be changed into a prime (205704727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1629 + ... + 20348.

Almost surely, 2^205704720 is an apocalyptic number.

205704720 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 205704720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (371999628).

205704720 is an abundant number, since it is smaller than the sum of its proper divisors (538294536).

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

205704720 is a wasteful number, since it uses less digits than its factorization.

205704720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22009 (or 22000 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 27.

The square root of 205704720 is about 14342.4098393541. The cubic root of 205704720 is about 590.3117379681.

The spelling of 205704720 in words is "two hundred five million, seven hundred four thousand, seven hundred twenty".