21131330210321 has 4 divisors (see below), whose sum is σ = 21134605884144. Its totient is φ = 21128054536500.

The previous prime is 21131330210311. The next prime is 21131330210339. The reversal of 21131330210321 is 12301203313112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21131330210321 - 2¹⁸ = 21131329948177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131330210311) 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, 1637827235 + ... + 1637840136.

It is an arithmetic number, because the mean of its divisors is an integer number (5283651471036).

Almost surely, 2^{21131330210321} is an apocalyptic number.

It is an amenable number.

21131330210321 is a deficient number, since it is larger than the sum of its proper divisors (3275673823).

21131330210321 is an equidigital number, since it uses as much as digits as its factorization.

21131330210321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3275673822.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 21131330210321 its reverse (12301203313112), we get a palindrome (33432533523433).

The spelling of 21131330210321 in words is "twenty-one trillion, one hundred thirty-one billion, three hundred thirty million, two hundred ten thousand, three hundred twenty-one".