20420004222421 has 4 divisors (see below), whose sum is σ = 20436838522252. Its totient is φ = 20403169922592.

The previous prime is 20420004222413. The next prime is 20420004222433. The reversal of 20420004222421 is 12422240002402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1314494352196 + 19105509870225 = 1146514^2 + 4370985^2 .

It is a cyclic number.

It is not a de Polignac number, because 20420004222421 - 2³ = 20420004222413 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 (20420004226421) 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, 8417148096 + ... + 8417150521.

It is an arithmetic number, because the mean of its divisors is an integer number (5109209630563).

Almost surely, 2^{20420004222421} is an apocalyptic number.

It is an amenable number.

20420004222421 is a deficient number, since it is larger than the sum of its proper divisors (16834299831).

20420004222421 is a wasteful number, since it uses less digits than its factorization.

20420004222421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16834299830.

The product of its (nonzero) digits is 4096, while the sum is 25.

Adding to 20420004222421 its reverse (12422240002402), we get a palindrome (32842244224823).

The spelling of 20420004222421 in words is "twenty trillion, four hundred twenty billion, four million, two hundred twenty-two thousand, four hundred twenty-one".