21002212202201 has 4 divisors (see below), whose sum is σ = 21726426416100. Its totient is φ = 20277997988304.

The previous prime is 21002212202189. The next prime is 21002212202219. The reversal of 21002212202201 is 10220221220012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8087539699600 + 12914672502601 = 2843860^2 + 3593699^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002212202201 - 2¹⁴ = 21002212185817 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002212202201.

It is not an unprimeable number, because it can be changed into a prime (21002214202201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 362107106906 + ... + 362107106963.

It is an arithmetic number, because the mean of its divisors is an integer number (5431606604025).

Almost surely, 2^{21002212202201} is an apocalyptic number.

It is an amenable number.

21002212202201 is a deficient number, since it is larger than the sum of its proper divisors (724214213899).

21002212202201 is an equidigital number, since it uses as much as digits as its factorization.

21002212202201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724214213898.

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

Adding to 21002212202201 its reverse (10220221220012), we get a palindrome (31222433422213).

The spelling of 21002212202201 in words is "twenty-one trillion, two billion, two hundred twelve million, two hundred two thousand, two hundred one".