220120100021 has 2 divisors, whose sum is σ = 220120100022. Its totient is φ = 220120100020.

The previous prime is 220120100003. The next prime is 220120100023. The reversal of 220120100021 is 120001021022.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214636697521 + 5483402500 = 463289^2 + 74050^2 .

It is a cyclic number.

It is not a de Polignac number, because 220120100021 - 2¹⁰ = 220120098997 is a prime.

Together with 220120100023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 220120099975 and 220120100011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220120100023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110060050010 + 110060050011.

It is an arithmetic number, because the mean of its divisors is an integer number (110060050011).

Almost surely, 2^220120100021 is an apocalyptic number.

It is an amenable number.

220120100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

220120100021 is an equidigital number, since it uses as much as digits as its factorization.

220120100021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 220120100021 its reverse (120001021022), we get a palindrome (340121121043).

The spelling of 220120100021 in words is "two hundred twenty billion, one hundred twenty million, one hundred thousand, twenty-one".