20022100400021 has 2 divisors, whose sum is σ = 20022100400022. Its totient is φ = 20022100400020.

The previous prime is 20022100400011. The next prime is 20022100400051. The reversal of 20022100400021 is 12000400122002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15993288703921 + 4028811696100 = 3999161^2 + 2007190^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20022100400021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20022100399969 and 20022100400005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20022100400011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10011050200010 + 10011050200011.

It is an arithmetic number, because the mean of its divisors is an integer number (10011050200011).

Almost surely, 2^{20022100400021} is an apocalyptic number.

It is an amenable number.

20022100400021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20022100400021 is an equidigital number, since it uses as much as digits as its factorization.

20022100400021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 20022100400021 its reverse (12000400122002), we get a palindrome (32022500522023).

The spelling of 20022100400021 in words is "twenty trillion, twenty-two billion, one hundred million, four hundred thousand, twenty-one".