204021090 has 192 divisors, whose sum is σ = 676166400. Its totient is φ = 41513472.

The previous prime is 204021089. The next prime is 204021101. The reversal of 204021090 is 90120402.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 237081 + ... + 237939.

It is an arithmetic number, because the mean of its divisors is an integer number (3521700).

Almost surely, 2^204021090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 204021090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (338083200).

204021090 is an abundant number, since it is smaller than the sum of its proper divisors (472145310).

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

204021090 is a wasteful number, since it uses less digits than its factorization.

204021090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921 (or 918 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 204021090 is about 14283.5951356793. The cubic root of 204021090 is about 588.6968172443.

Adding to 204021090 its reverse (90120402), we get a palindrome (294141492).

The spelling of 204021090 in words is "two hundred four million, twenty-one thousand, ninety".