204521540 has 12 divisors (see below), whose sum is σ = 429495276. Its totient is φ = 81808608.

The previous prime is 204521531. The next prime is 204521557. The reversal of 204521540 is 45125402.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 68425984 + 136095556 = 8272^2 + 11666^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5113019 + ... + 5113058.

It is an arithmetic number, because the mean of its divisors is an integer number (35791273).

Almost surely, 2^204521540 is an apocalyptic number.

204521540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

204521540 is an abundant number, since it is smaller than the sum of its proper divisors (224973736).

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

204521540 is a wasteful number, since it uses less digits than its factorization.

204521540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10226086 (or 10226084 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 204521540 is about 14301.1027546829. The cubic root of 204521540 is about 589.1777687659.

Adding to 204521540 its reverse (45125402), we get a palindrome (249646942).

The spelling of 204521540 in words is "two hundred four million, five hundred twenty-one thousand, five hundred forty".