21220201002001 has 4 divisors (see below), whose sum is σ = 21220803524404. Its totient is φ = 21219598479600.

The previous prime is 21220201001983. The next prime is 21220201002053. The reversal of 21220201002001 is 10020010202212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20652016713601 + 568184288400 = 4544449^2 + 753780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220201002001 - 2¹¹ = 21220200999953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220201002071) 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, 301208370 + ... + 301278811.

It is an arithmetic number, because the mean of its divisors is an integer number (5305200881101).

Almost surely, 2^{21220201002001} is an apocalyptic number.

It is an amenable number.

21220201002001 is a deficient number, since it is larger than the sum of its proper divisors (602522403).

21220201002001 is an equidigital number, since it uses as much as digits as its factorization.

21220201002001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602522402.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21220201002001 its reverse (10020010202212), we get a palindrome (31240211204213).

The spelling of 21220201002001 in words is "twenty-one trillion, two hundred twenty billion, two hundred one million, two thousand, one".