20421431220404 has 12 divisors (see below), whose sum is σ = 35763762914628. Its totient is φ = 10203213244800.

The previous prime is 20421431220373. The next prime is 20421431220517. The reversal of 20421431220404 is 40402213412402.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1647495468304 + 18773935752100 = 1283548^2 + 4332890^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1875585227 + ... + 1875596114.

It is an arithmetic number, because the mean of its divisors is an integer number (2980313576219).

Almost surely, 2^{20421431220404} is an apocalyptic number.

It is an amenable number.

20421431220404 is a deficient number, since it is larger than the sum of its proper divisors (15342331694224).

20421431220404 is a wasteful number, since it uses less digits than its factorization.

20421431220404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3751182706 (or 3751182704 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 29.

Adding to 20421431220404 its reverse (40402213412402), we get a palindrome (60823644632806).

The spelling of 20421431220404 in words is "twenty trillion, four hundred twenty-one billion, four hundred thirty-one million, two hundred twenty thousand, four hundred four".