20421505242404 has 96 divisors (see below), whose sum is σ = 41739183311616. Its totient is φ = 8561069936640.

The previous prime is 20421505242401. The next prime is 20421505242409. The reversal of 20421505242404 is 40424250512402.

It is not an unprimeable number, because it can be changed into a prime (20421505242401) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 727221644 + ... + 727249724.

It is an arithmetic number, because the mean of its divisors is an integer number (434783159496).

Almost surely, 2^{20421505242404} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421505242404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20869591655808).

20421505242404 is an abundant number, since it is smaller than the sum of its proper divisors (21317678069212).

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

20421505242404 is a wasteful number, since it uses less digits than its factorization.

20421505242404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29605 (or 29603 counting only the distinct ones).

The product of its (nonzero) digits is 102400, while the sum is 35.

Adding to 20421505242404 its reverse (40424250512402), we get a palindrome (60845755754806).

The spelling of 20421505242404 in words is "twenty trillion, four hundred twenty-one billion, five hundred five million, two hundred forty-two thousand, four hundred four".