21220111002001 has 4 divisors (see below), whose sum is σ = 21579773900400. Its totient is φ = 20860448103604.

The previous prime is 21220111001953. The next prime is 21220111002007. The reversal of 21220111002001 is 10020011102212.

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 21220111002001 - 2²¹ = 21220108904849 is a prime.

It is a super-2 number, since 2×21220111002001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220111002007) 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, 179831449111 + ... + 179831449228.

It is an arithmetic number, because the mean of its divisors is an integer number (5394943475100).

Almost surely, 2^{21220111002001} is an apocalyptic number.

It is an amenable number.

21220111002001 is a deficient number, since it is larger than the sum of its proper divisors (359662898399).

21220111002001 is an equidigital number, since it uses as much as digits as its factorization.

21220111002001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359662898398.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21220111002001 its reverse (10020011102212), we get a palindrome (31240122104213).

The spelling of 21220111002001 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, two thousand, one".