21011100021021 has 16 divisors (see below), whose sum is σ = 31272334917120. Its totient is φ = 12437860476720.

The previous prime is 21011100020983. The next prime is 21011100021047. The reversal of 21011100021021 is 12012000111012.

It is not a de Polignac number, because 21011100021021 - 2⁷ = 21011100020893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011100020988 and 21011100021006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011100021061) 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, 7403486961 + ... + 7403489798.

It is an arithmetic number, because the mean of its divisors is an integer number (1954520932320).

Almost surely, 2^{21011100021021} is an apocalyptic number.

It is an amenable number.

21011100021021 is a deficient number, since it is larger than the sum of its proper divisors (10261234896099).

21011100021021 is a wasteful number, since it uses less digits than its factorization.

21011100021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14806976816.

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

Adding to 21011100021021 its reverse (12012000111012), we get a palindrome (33023100132033).

The spelling of 21011100021021 in words is "twenty-one trillion, eleven billion, one hundred million, twenty-one thousand, twenty-one".