21321213111001 has 4 divisors (see below), whose sum is σ = 21321274877604. Its totient is φ = 21321151344400.

The previous prime is 21321213110947. The next prime is 21321213111041. The reversal of 21321213111001 is 10011131212312.

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 6263126885376 + 15058086225625 = 2502624^2 + 3880475^2 .

It is a cyclic number.

It is not a de Polignac number, because 21321213111001 - 2⁹ = 21321213110489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21321213111001.

It is not an unprimeable number, because it can be changed into a prime (21321213111041) 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, 30362590 + ... + 31056871.

It is an arithmetic number, because the mean of its divisors is an integer number (5330318719401).

Almost surely, 2^{21321213111001} is an apocalyptic number.

It is an amenable number.

21321213111001 is a deficient number, since it is larger than the sum of its proper divisors (61766603).

21321213111001 is an equidigital number, since it uses as much as digits as its factorization.

21321213111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61766602.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 21321213111001 its reverse (10011131212312), we get a palindrome (31332344323313).

The spelling of 21321213111001 in words is "twenty-one trillion, three hundred twenty-one billion, two hundred thirteen million, one hundred eleven thousand, one".