21100010220021 has 4 divisors (see below), whose sum is σ = 28133346960032. Its totient is φ = 14066673480012.

The previous prime is 21100010220007. The next prime is 21100010220061. The reversal of 21100010220021 is 12002201000112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21100010220021 - 2⁴³ = 12303917197813 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100010219979 and 21100010220006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100010220001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3516668370001 + ... + 3516668370006.

It is an arithmetic number, because the mean of its divisors is an integer number (7033336740008).

Almost surely, 2^{21100010220021} is an apocalyptic number.

It is an amenable number.

21100010220021 is a deficient number, since it is larger than the sum of its proper divisors (7033336740011).

21100010220021 is an equidigital number, since it uses as much as digits as its factorization.

21100010220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7033336740010.

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

Adding to 21100010220021 its reverse (12002201000112), we get a palindrome (33102211220133).

The spelling of 21100010220021 in words is "twenty-one trillion, one hundred billion, ten million, two hundred twenty thousand, twenty-one".