204420090 has 64 divisors (see below), whose sum is σ = 585086976. Its totient is φ = 44692032.

The previous prime is 204420077. The next prime is 204420109. The reversal of 204420090 is 90024402.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16332 + ... + 25991.

It is an arithmetic number, because the mean of its divisors is an integer number (9141984).

Almost surely, 2^204420090 is an apocalyptic number.

204420090 is an abundant number, since it is smaller than the sum of its proper divisors (380666886).

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

204420090 is a wasteful number, since it uses less digits than its factorization.

204420090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42363.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 204420090 is about 14297.5553854496. Note that the first 3 decimals coincide. The cubic root of 204420090 is about 589.0803349041.

Adding to 204420090 its reverse (90024402), we get a palindrome (294444492).

The spelling of 204420090 in words is "two hundred four million, four hundred twenty thousand, ninety".