20121120121 has 4 divisors (see below), whose sum is σ = 20770188544. Its totient is φ = 19472051700.

The previous prime is 20121120079. The next prime is 20121120127. The reversal of 20121120121 is 12102112102.

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 not a de Polignac number, because 20121120121 - 2⁹ = 20121119609 is a prime.

It is a super-2 number, since 2×20121120121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121120127) 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 3 ways as a sum of consecutive naturals, for example, 324534165 + ... + 324534226.

It is an arithmetic number, because the mean of its divisors is an integer number (5192547136).

Almost surely, 2^20121120121 is an apocalyptic number.

It is an amenable number.

20121120121 is a deficient number, since it is larger than the sum of its proper divisors (649068423).

20121120121 is an equidigital number, since it uses as much as digits as its factorization.

20121120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649068422.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20121120121 its reverse (12102112102), we get a palindrome (32223232223).

The spelling of 20121120121 in words is "twenty billion, one hundred twenty-one million, one hundred twenty thousand, one hundred twenty-one".