20102121211021 has 4 divisors (see below), whose sum is σ = 20115786828544. Its totient is φ = 20088455593500.

The previous prime is 20102121211019. The next prime is 20102121211091. The reversal of 20102121211021 is 12011212120102.

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 20102121211021 - 2¹ = 20102121211019 is a prime.

It is a super-2 number, since 2×20102121211021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20102121210986 and 20102121211004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102121211091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6832806555 + ... + 6832809496.

It is an arithmetic number, because the mean of its divisors is an integer number (5028946707136).

Almost surely, 2^{20102121211021} is an apocalyptic number.

It is an amenable number.

20102121211021 is a deficient number, since it is larger than the sum of its proper divisors (13665617523).

20102121211021 is a wasteful number, since it uses less digits than its factorization.

20102121211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13665617522.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 20102121211021 its reverse (12011212120102), we get a palindrome (32113333331123).

The spelling of 20102121211021 in words is "twenty trillion, one hundred two billion, one hundred twenty-one million, two hundred eleven thousand, twenty-one".