21202012012221 has 24 divisors (see below), whose sum is σ = 31961870006976. Its totient is φ = 13517917585920.

The previous prime is 21202012012201. The next prime is 21202012012243. The reversal of 21202012012221 is 12221021020212.

It is a happy number.

21202012012221 is a `hidden beast` number, since 21 + 20 + 201 + 201 + 2 + 221 = 666.

It is not a de Polignac number, because 21202012012221 - 2⁵ = 21202012012189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202012012194 and 21202012012203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202012012201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7083940 + ... + 9622173.

It is an arithmetic number, because the mean of its divisors is an integer number (1331744583624).

Almost surely, 2^{21202012012221} is an apocalyptic number.

It is an amenable number.

21202012012221 is a deficient number, since it is larger than the sum of its proper divisors (10759857994755).

21202012012221 is a wasteful number, since it uses less digits than its factorization.

21202012012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16712273 (or 16712270 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21202012012221 its reverse (12221021020212), we get a palindrome (33423033032433).

The spelling of 21202012012221 in words is "twenty-one trillion, two hundred two billion, twelve million, twelve thousand, two hundred twenty-one".