21101220211001 has 4 divisors (see below), whose sum is σ = 24115680241152. Its totient is φ = 18086760180852.

The previous prime is 21101220210997. The next prime is 21101220211007. The reversal of 21101220211001 is 10011202210112.

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 21101220211001 - 2² = 21101220210997 is a prime.

It is a super-2 number, since 2×21101220211001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21101220211007) 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, 1507230015065 + ... + 1507230015078.

It is an arithmetic number, because the mean of its divisors is an integer number (6028920060288).

Almost surely, 2^{21101220211001} is an apocalyptic number.

It is an amenable number.

21101220211001 is a deficient number, since it is larger than the sum of its proper divisors (3014460030151).

21101220211001 is an equidigital number, since it uses as much as digits as its factorization.

21101220211001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3014460030150.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21101220211001 its reverse (10011202210112), we get a palindrome (31112422421113).

The spelling of 21101220211001 in words is "twenty-one trillion, one hundred one billion, two hundred twenty million, two hundred eleven thousand, one".