20021221112121 has 12 divisors (see below), whose sum is σ = 28930209122880. Its totient is φ = 13342557272280.

The previous prime is 20021221112089. The next prime is 20021221112131. The reversal of 20021221112121 is 12121112212002.

20021221112121 is a `hidden beast` number, since 200 + 21 + 221 + 11 + 212 + 1 = 666.

It is not a de Polignac number, because 20021221112121 - 2⁵ = 20021221112089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20021221112094 and 20021221112103.

It is not an unprimeable number, because it can be changed into a prime (20021221112131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 410263341 + ... + 410312138.

It is an arithmetic number, because the mean of its divisors is an integer number (2410850760240).

Almost surely, 2^{20021221112121} is an apocalyptic number.

It is an amenable number.

20021221112121 is a deficient number, since it is larger than the sum of its proper divisors (8908988010759).

20021221112121 is a wasteful number, since it uses less digits than its factorization.

20021221112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820578196 (or 820578193 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 20021221112121 its reverse (12121112212002), we get a palindrome (32142333324123).

The spelling of 20021221112121 in words is "twenty trillion, twenty-one billion, two hundred twenty-one million, one hundred twelve thousand, one hundred twenty-one".