21020013101023 has 4 divisors (see below), whose sum is σ = 21030251784568. Its totient is φ = 21009774417480.

The previous prime is 21020013100997. The next prime is 21020013101077. The reversal of 21020013101023 is 32010131002012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21020013101023 - 2³⁷ = 20882574147551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020013100988 and 21020013101006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020013101123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5119338693 + ... + 5119342798.

It is an arithmetic number, because the mean of its divisors is an integer number (5257562946142).

Almost surely, 2^{21020013101023} is an apocalyptic number.

21020013101023 is a deficient number, since it is larger than the sum of its proper divisors (10238683545).

21020013101023 is a wasteful number, since it uses less digits than its factorization.

21020013101023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10238683544.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21020013101023 its reverse (32010131002012), we get a palindrome (53030144103035).

The spelling of 21020013101023 in words is "twenty-one trillion, twenty billion, thirteen million, one hundred one thousand, twenty-three".