21210220202201 has 4 divisors (see below), whose sum is σ = 21214574594304. Its totient is φ = 21205865810100.

The previous prime is 21210220202189. The next prime is 21210220202207. The reversal of 21210220202201 is 10220202201212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210220202201 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 21210220202201.

It is not an unprimeable number, because it can be changed into a prime (21210220202207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2177188745 + ... + 2177198486.

It is an arithmetic number, because the mean of its divisors is an integer number (5303643648576).

Almost surely, 2^{21210220202201} is an apocalyptic number.

It is an amenable number.

21210220202201 is a deficient number, since it is larger than the sum of its proper divisors (4354392103).

21210220202201 is an equidigital number, since it uses as much as digits as its factorization.

21210220202201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4354392102.

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

Adding to 21210220202201 its reverse (10220202201212), we get a palindrome (31430422403413).

It can be divided in two parts, 212 and 10220202201, that multiplied together give a palindrome (2166682866612).

The spelling of 21210220202201 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, two hundred two thousand, two hundred one".