204221220 has 72 divisors (see below), whose sum is σ = 665187264. Its totient is φ = 46678464.

The previous prime is 204221197. The next prime is 204221261. The reversal of 204221220 is 22122402.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 204221220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31792 + ... + 37671.

It is an arithmetic number, because the mean of its divisors is an integer number (9238712).

Almost surely, 2^204221220 is an apocalyptic number.

204221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

204221220 is an abundant number, since it is smaller than the sum of its proper divisors (460966044).

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

204221220 is a wasteful number, since it uses less digits than its factorization.

204221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69489 (or 69480 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 204221220 is about 14290.5990077393. The cubic root of 204221220 is about 588.8892440698.

Adding to 204221220 its reverse (22122402), we get a palindrome (226343622).

The spelling of 204221220 in words is "two hundred four million, two hundred twenty-one thousand, two hundred twenty".