20021121012221 has 16 divisors (see below), whose sum is σ = 23259142831488. Its totient is φ = 16877631355200.

The previous prime is 20021121012001. The next prime is 20021121012239. The reversal of 20021121012221 is 12221012112002.

It is not a de Polignac number, because 20021121012221 - 2²² = 20021116817917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20021121012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021121012241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 828431 + ... + 6381891.

It is an arithmetic number, because the mean of its divisors is an integer number (1453696426968).

Almost surely, 2^{20021121012221} is an apocalyptic number.

It is an amenable number.

20021121012221 is a deficient number, since it is larger than the sum of its proper divisors (3238021819267).

20021121012221 is an equidigital number, since it uses as much as digits as its factorization.

20021121012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5561972.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20021121012221 its reverse (12221012112002), we get a palindrome (32242133124223).

The spelling of 20021121012221 in words is "twenty trillion, twenty-one billion, one hundred twenty-one million, twelve thousand, two hundred twenty-one".