21201221201 has 4 divisors (see below), whose sum is σ = 21201610752. Its totient is φ = 21200831652.

The previous prime is 21201221189. The next prime is 21201221207. The reversal of 21201221201 is 10212210212.

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 not a de Polignac number, because 21201221201 - 2⁶ = 21201221137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201221207) 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, 96665 + ... + 227478.

It is an arithmetic number, because the mean of its divisors is an integer number (5300402688).

Almost surely, 2^21201221201 is an apocalyptic number.

It is an amenable number.

21201221201 is a deficient number, since it is larger than the sum of its proper divisors (389551).

21201221201 is an equidigital number, since it uses as much as digits as its factorization.

21201221201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389550.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21201221201 its reverse (10212210212), we get a palindrome (31413431413).

The spelling of 21201221201 in words is "twenty-one billion, two hundred one million, two hundred twenty-one thousand, two hundred one".