20121220000021 has 16 divisors (see below), whose sum is σ = 23385906593280. Its totient is φ = 16954101788400.

The previous prime is 20121220000003. The next prime is 20121220000039. The reversal of 20121220000021 is 12000002212102.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20121220000003) and next prime (20121220000039).

It is not a de Polignac number, because 20121220000021 - 2⁵ = 20121219999989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121219999956 and 20121220000010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121220000081) 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, 21288946 + ... + 22213996.

It is an arithmetic number, because the mean of its divisors is an integer number (1461619162080).

Almost surely, 2^{20121220000021} is an apocalyptic number.

It is an amenable number.

20121220000021 is a deficient number, since it is larger than the sum of its proper divisors (3264686593259).

20121220000021 is an equidigital number, since it uses as much as digits as its factorization.

20121220000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977784.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20121220000021 its reverse (12000002212102), we get a palindrome (32121222212123).

The spelling of 20121220000021 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty million, twenty-one", and thus it is an aban number.