21101010021021 has 16 divisors (see below), whose sum is σ = 32234104384128. Its totient is φ = 12027650880000.

The previous prime is 21101010021011. The next prime is 21101010021031. The reversal of 21101010021021 is 12012001010112.

It is an interprime number because it is at equal distance from previous prime (21101010021011) and next prime (21101010021031).

It is not a de Polignac number, because 21101010021021 - 2⁶ = 21101010020957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21101010020988 and 21101010021006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101010021011) 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, 1252871880 + ... + 1252888721.

It is an arithmetic number, because the mean of its divisors is an integer number (2014631524008).

Almost surely, 2^{21101010021021} is an apocalyptic number.

21101010021021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21101010021021 is a deficient number, since it is larger than the sum of its proper divisors (11133094363107).

21101010021021 is a wasteful number, since it uses less digits than its factorization.

21101010021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2505761012.

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

Adding to 21101010021021 its reverse (12012001010112), we get a palindrome (33113011031133).

The spelling of 21101010021021 in words is "twenty-one trillion, one hundred one billion, ten million, twenty-one thousand, twenty-one".