20421305344 has 176 divisors, whose sum is σ = 46054552320. Its totient is φ = 8971223040.

The previous prime is 20421305329. The next prime is 20421305363. The reversal of 20421305344 is 44350312402.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (176).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47162152 + ... + 47162584.

Almost surely, 2^20421305344 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 20421305344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23027276160).

20421305344 is an abundant number, since it is smaller than the sum of its proper divisors (25633246976).

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

20421305344 is a wasteful number, since it uses less digits than its factorization.

20421305344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 578 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 20421305344 its reverse (44350312402), we get a palindrome (64771617746).

The spelling of 20421305344 in words is "twenty billion, four hundred twenty-one million, three hundred five thousand, three hundred forty-four".