21221211101201 has 4 divisors (see below), whose sum is σ = 21221271321600. Its totient is φ = 21221150880804.

The previous prime is 21221211101159. The next prime is 21221211101249. The reversal of 21221211101201 is 10210111212212.

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-21221211101201 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 21221211101201.

It is not an unprimeable number, because it can be changed into a prime (21221211101261) 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, 29578481 + ... + 30287438.

It is an arithmetic number, because the mean of its divisors is an integer number (5305317830400).

Almost surely, 2^{21221211101201} is an apocalyptic number.

It is an amenable number.

21221211101201 is a deficient number, since it is larger than the sum of its proper divisors (60220399).

21221211101201 is an equidigital number, since it uses as much as digits as its factorization.

21221211101201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60220398.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21221211101201 its reverse (10210111212212), we get a palindrome (31431322313413).

The spelling of 21221211101201 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred one thousand, two hundred one".