21020121010101 has 96 divisors (see below), whose sum is σ = 30829895107200. Its totient is φ = 12721209177600.

The previous prime is 21020121010039. The next prime is 21020121010121. The reversal of 21020121010101 is 10101012102012.

It is not a de Polignac number, because 21020121010101 - 2¹⁸ = 21020120747957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020121010121) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 646100631 + ... + 646133163.

It is an arithmetic number, because the mean of its divisors is an integer number (321144740700).

Almost surely, 2^{21020121010101} is an apocalyptic number.

It is an amenable number.

21020121010101 is a deficient number, since it is larger than the sum of its proper divisors (9809774097099).

21020121010101 is a wasteful number, since it uses less digits than its factorization.

21020121010101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32851 (or 32828 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21020121010101 its reverse (10101012102012), we get a palindrome (31121133112113).

It can be divided in two parts, 2102012 and 1010101, that multiplied together give a palindrome (2123244423212).

The spelling of 21020121010101 in words is "twenty-one trillion, twenty billion, one hundred twenty-one million, ten thousand, one hundred one".