21012110203221 has 40 divisors (see below), whose sum is σ = 32485345108920. Its totient is φ = 13518987011712.

The previous prime is 21012110203213. The next prime is 21012110203319. The reversal of 21012110203221 is 12230201121012.

21012110203221 is a `hidden beast` number, since 210 + 1 + 2 + 110 + 20 + 322 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1872753932196 + 19139356271025 = 1368486^2 + 4374855^2 .

It is not a de Polignac number, because 21012110203221 - 2³ = 21012110203213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012110203194 and 21012110203203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012110203321) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3255355 + ... + 7254071.

It is an arithmetic number, because the mean of its divisors is an integer number (812133627723).

Almost surely, 2^{21012110203221} is an apocalyptic number.

It is an amenable number.

21012110203221 is a deficient number, since it is larger than the sum of its proper divisors (11473234905699).

21012110203221 is a wasteful number, since it uses less digits than its factorization.

21012110203221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4000995 (or 4000986 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21012110203221 its reverse (12230201121012), we get a palindrome (33242311324233).

The spelling of 21012110203221 in words is "twenty-one trillion, twelve billion, one hundred ten million, two hundred three thousand, two hundred twenty-one".