21010020020121 has 16 divisors (see below), whose sum is σ = 31270727473920. Its totient is φ = 12437221152720.

The previous prime is 21010020020111. The next prime is 21010020020161. The reversal of 21010020020121 is 12102002001012.

It is not a de Polignac number, because 21010020020121 - 2⁷ = 21010020019993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21010020020097 and 21010020020106.

It is not an unprimeable number, because it can be changed into a prime (21010020020111) 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, 7403106411 + ... + 7403109248.

It is an arithmetic number, because the mean of its divisors is an integer number (1954420467120).

Almost surely, 2^{21010020020121} is an apocalyptic number.

It is an amenable number.

21010020020121 is a deficient number, since it is larger than the sum of its proper divisors (10260707453799).

21010020020121 is a wasteful number, since it uses less digits than its factorization.

21010020020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14806215716.

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

Adding to 21010020020121 its reverse (12102002001012), we get a palindrome (33112022021133).

The spelling of 21010020020121 in words is "twenty-one trillion, ten billion, twenty million, twenty thousand, one hundred twenty-one".