12221202120021 has 18 divisors (see below), whose sum is σ = 17689173174582. Its totient is φ = 8130736746000.

The previous prime is 12221202120019. The next prime is 12221202120109. The reversal of 12221202120021 is 12002120212221.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 9279243054225 + 2941959065796 = 3046185^2 + 1715214^2 .

It is not a de Polignac number, because 12221202120021 - 2¹ = 12221202120019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12221202119976 and 12221202120003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221202120821) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 728230 + ... + 4997271.

Almost surely, 2^{12221202120021} is an apocalyptic number.

It is an amenable number.

12221202120021 is a deficient number, since it is larger than the sum of its proper divisors (5467971054561).

12221202120021 is an frugal number, since it uses more digits than its factorization.

12221202120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5726481 (or 5725991 counting only the distinct ones).

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

Adding to 12221202120021 its reverse (12002120212221), we get a palindrome (24223322332242).

The spelling of 12221202120021 in words is "twelve trillion, two hundred twenty-one billion, two hundred two million, one hundred twenty thousand, twenty-one".