20101220001021 has 4 divisors (see below), whose sum is σ = 26801626668032. Its totient is φ = 13400813334012.

The previous prime is 20101220001007. The next prime is 20101220001029. The reversal of 20101220001021 is 12010002210102.

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 20101220001021 - 2¹⁰ = 20101219999997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20101220000988 and 20101220001006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101220001029) 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, 3350203333501 + ... + 3350203333506.

It is an arithmetic number, because the mean of its divisors is an integer number (6700406667008).

Almost surely, 2^{20101220001021} is an apocalyptic number.

It is an amenable number.

20101220001021 is a deficient number, since it is larger than the sum of its proper divisors (6700406667011).

20101220001021 is an equidigital number, since it uses as much as digits as its factorization.

20101220001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6700406667010.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20101220001021 its reverse (12010002210102), we get a palindrome (32111222211123).

The spelling of 20101220001021 in words is "twenty trillion, one hundred one billion, two hundred twenty million, one thousand, twenty-one".