205621120 has 64 divisors (see below), whose sum is σ = 520506000. Its totient is φ = 77406208.

The previous prime is 205621093. The next prime is 205621123. The reversal of 205621120 is 21126502.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205621123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1431 + ... + 20329.

Almost surely, 2^205621120 is an apocalyptic number.

205621120 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 205621120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260253000).

205621120 is an abundant number, since it is smaller than the sum of its proper divisors (314884880).

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

205621120 is a wasteful number, since it uses less digits than its factorization.

205621120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18935 (or 18923 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 205621120 is about 14339.4951096613. The cubic root of 205621120 is about 590.2317580367.

Adding to 205621120 its reverse (21126502), we get a palindrome (226747622).

The spelling of 205621120 in words is "two hundred five million, six hundred twenty-one thousand, one hundred twenty".