21211302121001 has 4 divisors (see below), whose sum is σ = 21942726332100. Its totient is φ = 20479877909904.

The previous prime is 21211302120961. The next prime is 21211302121033. The reversal of 21211302121001 is 10012120311212.

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 16639505514025 + 4571796606976 = 4079155^2 + 2138176^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211302121001 - 2³⁴ = 21194122251817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21211302121091) 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, 365712105506 + ... + 365712105563.

It is an arithmetic number, because the mean of its divisors is an integer number (5485681583025).

Almost surely, 2^{21211302121001} is an apocalyptic number.

It is an amenable number.

21211302121001 is a deficient number, since it is larger than the sum of its proper divisors (731424211099).

21211302121001 is an equidigital number, since it uses as much as digits as its factorization.

21211302121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731424211098.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21211302121001 its reverse (10012120311212), we get a palindrome (31223422432213).

The spelling of 21211302121001 in words is "twenty-one trillion, two hundred eleven billion, three hundred two million, one hundred twenty-one thousand, one".