204431021421 has 16 divisors (see below), whose sum is σ = 297420787008. Its totient is φ = 123869849600.

The previous prime is 204431021363. The next prime is 204431021429. The reversal of 204431021421 is 124120134402.

It is a cyclic number.

It is not a de Polignac number, because 204431021421 - 2⁹ = 204431020909 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 204431021391 and 204431021400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204431021429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 543366 + ... + 839111.

It is an arithmetic number, because the mean of its divisors is an integer number (18588799188).

Almost surely, 2^204431021421 is an apocalyptic number.

It is an amenable number.

204431021421 is a deficient number, since it is larger than the sum of its proper divisors (92989765587).

204431021421 is a wasteful number, since it uses less digits than its factorization.

204431021421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386972.

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 204431021421 its reverse (124120134402), we get a palindrome (328551155823).

The spelling of 204431021421 in words is "two hundred four billion, four hundred thirty-one million, twenty-one thousand, four hundred twenty-one".