21000112020021 has 16 divisors (see below), whose sum is σ = 28596144870144. Its totient is φ = 13702082084544.

The previous prime is 21000112020007. The next prime is 21000112020023. The reversal of 21000112020021 is 12002021100012.

It is a de Polignac number, because none of the positive numbers 2^k-21000112020021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000112019979 and 21000112020006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000112020023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17497215 + ... + 18658851.

It is an arithmetic number, because the mean of its divisors is an integer number (1787259054384).

Almost surely, 2^{21000112020021} is an apocalyptic number.

It is an amenable number.

21000112020021 is a deficient number, since it is larger than the sum of its proper divisors (7596032850123).

21000112020021 is a wasteful number, since it uses less digits than its factorization.

21000112020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1289900.

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

Adding to 21000112020021 its reverse (12002021100012), we get a palindrome (33002133120033).

The spelling of 21000112020021 in words is "twenty-one trillion, one hundred twelve million, twenty thousand, twenty-one".