21010121012221 has 32 divisors (see below), whose sum is σ = 23392996816896. Its totient is φ = 18710196480000.

The previous prime is 21010121012191. The next prime is 21010121012263. The reversal of 21010121012221 is 12221012101012.

It is a cyclic number.

It is not a de Polignac number, because 21010121012221 - 2⁵ = 21010121012189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010121012195 and 21010121012204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010121012281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 365409151 + ... + 365466643.

It is an arithmetic number, because the mean of its divisors is an integer number (731031150528).

Almost surely, 2^{21010121012221} is an apocalyptic number.

It is an amenable number.

21010121012221 is a deficient number, since it is larger than the sum of its proper divisors (2382875804675).

21010121012221 is a wasteful number, since it uses less digits than its factorization.

21010121012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61093.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21010121012221 its reverse (12221012101012), we get a palindrome (33231133113233).

The spelling of 21010121012221 in words is "twenty-one trillion, ten billion, one hundred twenty-one million, twelve thousand, two hundred twenty-one".