21020121112113 has 6 divisors (see below), whose sum is σ = 30362397161954. Its totient is φ = 14013414074736.

The previous prime is 21020121112091. The next prime is 21020121112157. The reversal of 21020121112113 is 31121112102012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18835660760049 + 2184460352064 = 4340007^2 + 1477992^2 .

It is not a de Polignac number, because 21020121112113 - 2¹² = 21020121108017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020121112013) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1167784506220 + ... + 1167784506237.

Almost surely, 2^{21020121112113} is an apocalyptic number.

It is an amenable number.

21020121112113 is a deficient number, since it is larger than the sum of its proper divisors (9342276049841).

21020121112113 is a wasteful number, since it uses less digits than its factorization.

21020121112113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2335569012463 (or 2335569012460 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 21020121112113 its reverse (31121112102012), we get a palindrome (52141233214125).

The spelling of 21020121112113 in words is "twenty-one trillion, twenty billion, one hundred twenty-one million, one hundred twelve thousand, one hundred thirteen".