21021003222001 has 4 divisors (see below), whose sum is σ = 21745865402100. Its totient is φ = 20296141041904.

The previous prime is 21021003221987. The next prime is 21021003222091. The reversal of 21021003222001 is 10022230012012.

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 7405604312976 + 13615398909025 = 2721324^2 + 3689905^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021003222001 - 2²³ = 21020994833393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021003222091) 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, 362431090006 + ... + 362431090063.

It is an arithmetic number, because the mean of its divisors is an integer number (5436466350525).

Almost surely, 2^{21021003222001} is an apocalyptic number.

It is an amenable number.

21021003222001 is a deficient number, since it is larger than the sum of its proper divisors (724862180099).

21021003222001 is an equidigital number, since it uses as much as digits as its factorization.

21021003222001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724862180098.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21021003222001 its reverse (10022230012012), we get a palindrome (31043233234013).

The spelling of 21021003222001 in words is "twenty-one trillion, twenty-one billion, three million, two hundred twenty-two thousand, one".