21012231424321 has 2 divisors, whose sum is σ = 21012231424322. Its totient is φ = 21012231424320.

The previous prime is 21012231424309. The next prime is 21012231424339. The reversal of 21012231424321 is 12342413221012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11616099897600 + 9396131526721 = 3408240^2 + 3065311^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012231424321 - 2⁹ = 21012231423809 is a prime.

It is a super-2 number, since 2×21012231424321² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21012231424321.

It is not a weakly prime, because it can be changed into another prime (21012231425321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506115712160 + 10506115712161.

It is an arithmetic number, because the mean of its divisors is an integer number (10506115712161).

Almost surely, 2^{21012231424321} is an apocalyptic number.

It is an amenable number.

21012231424321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012231424321 is an equidigital number, since it uses as much as digits as its factorization.

21012231424321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 28.

Adding to 21012231424321 its reverse (12342413221012), we get a palindrome (33354644645333).

The spelling of 21012231424321 in words is "twenty-one trillion, twelve billion, two hundred thirty-one million, four hundred twenty-four thousand, three hundred twenty-one".