20001221120121 has 8 divisors (see below), whose sum is σ = 26912958082560. Its totient is φ = 13211815785552.

The previous prime is 20001221120117. The next prime is 20001221120129. The reversal of 20001221120121 is 12102112210002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20001221120121 - 2² = 20001221120117 is a prime.

It is a super-2 number, since 2×20001221120121² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20001221120121.

It is not an unprimeable number, because it can be changed into a prime (20001221120129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30582906585 + ... + 30582907238.

It is an arithmetic number, because the mean of its divisors is an integer number (3364119760320).

Almost surely, 2^{20001221120121} is an apocalyptic number.

It is an amenable number.

20001221120121 is a deficient number, since it is larger than the sum of its proper divisors (6911736962439).

20001221120121 is a wasteful number, since it uses less digits than its factorization.

20001221120121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61165813935.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20001221120121 its reverse (12102112210002), we get a palindrome (32103333330123).

The spelling of 20001221120121 in words is "twenty trillion, one billion, two hundred twenty-one million, one hundred twenty thousand, one hundred twenty-one".