20101220120221 has 4 divisors (see below), whose sum is σ = 20749646575744. Its totient is φ = 19452793664700.

The previous prime is 20101220120207. The next prime is 20101220120239. The reversal of 20101220120221 is 12202102210102.

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 20101220120221 - 2²⁷ = 20101085902493 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20101220120195 and 20101220120204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101220120521) 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, 324213227715 + ... + 324213227776.

It is an arithmetic number, because the mean of its divisors is an integer number (5187411643936).

Almost surely, 2^{20101220120221} is an apocalyptic number.

It is an amenable number.

20101220120221 is a deficient number, since it is larger than the sum of its proper divisors (648426455523).

20101220120221 is an equidigital number, since it uses as much as digits as its factorization.

20101220120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648426455522.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20101220120221 its reverse (12202102210102), we get a palindrome (32303322330323).

The spelling of 20101220120221 in words is "twenty trillion, one hundred one billion, two hundred twenty million, one hundred twenty thousand, two hundred twenty-one".