20421344101 has 4 divisors (see below), whose sum is σ = 20855840832. Its totient is φ = 19986847372.

The previous prime is 20421344093. The next prime is 20421344107. The reversal of 20421344101 is 10144312402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20421344101 - 2³ = 20421344093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421344107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217248295 + ... + 217248388.

It is an arithmetic number, because the mean of its divisors is an integer number (5213960208).

Almost surely, 2^20421344101 is an apocalyptic number.

It is an amenable number.

20421344101 is a deficient number, since it is larger than the sum of its proper divisors (434496731).

20421344101 is an equidigital number, since it uses as much as digits as its factorization.

20421344101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434496730.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 20421344101 its reverse (10144312402), we get a palindrome (30565656503).

The spelling of 20421344101 in words is "twenty billion, four hundred twenty-one million, three hundred forty-four thousand, one hundred one".