205721450 has 24 divisors (see below), whose sum is σ = 417428640. Its totient is φ = 74807600.

The previous prime is 205721449. The next prime is 205721459. The reversal of 205721450 is 54127502.

It is not an unprimeable number, because it can be changed into a prime (205721459) 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 11 ways as a sum of consecutive naturals, for example, 186470 + ... + 187569.

It is an arithmetic number, because the mean of its divisors is an integer number (17392860).

Almost surely, 2^205721450 is an apocalyptic number.

205721450 is an abundant number, since it is smaller than the sum of its proper divisors (211707190).

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

205721450 is a wasteful number, since it uses less digits than its factorization.

205721450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374062 (or 374057 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 205721450 is about 14342.9930628164. The cubic root of 205721450 is about 590.3277409191.

Adding to 205721450 its reverse (54127502), we get a palindrome (259848952).

It can be divided in two parts, 20572 and 1450, that added together give a palindrome (22022).

The spelling of 205721450 in words is "two hundred five million, seven hundred twenty-one thousand, four hundred fifty".