21102220220021 has 8 divisors (see below), whose sum is σ = 21828412876800. Its totient is φ = 20378869805520.

The previous prime is 21102220219981. The next prime is 21102220220069. The reversal of 21102220220021 is 12002202220112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21102220220021 - 2⁶ = 21102220219957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102220220071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 710545466 + ... + 710575163.

It is an arithmetic number, because the mean of its divisors is an integer number (2728551609600).

Almost surely, 2^{21102220220021} is an apocalyptic number.

It is an amenable number.

21102220220021 is a deficient number, since it is larger than the sum of its proper divisors (726192656779).

21102220220021 is a wasteful number, since it uses less digits than its factorization.

21102220220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1421121139.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21102220220021 its reverse (12002202220112), we get a palindrome (33104422440133).

The spelling of 21102220220021 in words is "twenty-one trillion, one hundred two billion, two hundred twenty million, two hundred twenty thousand, twenty-one".