204021525421 has 16 divisors (see below), whose sum is σ = 233855285760. Its totient is φ = 174359940480.

The previous prime is 204021525373. The next prime is 204021525439. The reversal of 204021525421 is 124525120402.

It is a happy number.

204021525421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204021525421 is a prime.

It is a super-2 number, since 2×204021525421² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204021525421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204021523421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22266081 + ... + 22275241.

It is an arithmetic number, because the mean of its divisors is an integer number (14615955360).

Almost surely, 2^204021525421 is an apocalyptic number.

It is an amenable number.

204021525421 is a deficient number, since it is larger than the sum of its proper divisors (29833760339).

204021525421 is an equidigital number, since it uses as much as digits as its factorization.

204021525421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18204.

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 204021525421 its reverse (124525120402), we get a palindrome (328546645823).

The spelling of 204021525421 in words is "two hundred four billion, twenty-one million, five hundred twenty-five thousand, four hundred twenty-one".