12121010001221 has 4 divisors (see below), whose sum is σ = 13222920001344. Its totient is φ = 11019100001100.

The previous prime is 12121010001187. The next prime is 12121010001229. The reversal of 12121010001221 is 12210001012121.

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 12121010001221 - 2⁶ = 12121010001157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121010001196 and 12121010001205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121010001229) 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, 550955000045 + ... + 550955000066.

It is an arithmetic number, because the mean of its divisors is an integer number (3305730000336).

Almost surely, 2^{12121010001221} is an apocalyptic number.

12121010001221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12121010001221 is a deficient number, since it is larger than the sum of its proper divisors (1101910000123).

12121010001221 is a wasteful number, since it uses less digits than its factorization.

12121010001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101910000122.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 12121010001221 its reverse (12210001012121), we get a palindrome (24331011013342).

The spelling of 12121010001221 in words is "twelve trillion, one hundred twenty-one billion, ten million, one thousand, two hundred twenty-one".