21103121210321 has 16 divisors (see below), whose sum is σ = 21874514558976. Its totient is φ = 20345181033936.

The previous prime is 21103121210299. The next prime is 21103121210329. The reversal of 21103121210321 is 12301212130112.

It is a cyclic number.

It is not a de Polignac number, because 21103121210321 - 2¹⁴ = 21103121193937 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21103121210293 and 21103121210302.

It is not an unprimeable number, because it can be changed into a prime (21103121210329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115120880 + ... + 115304046.

It is an arithmetic number, because the mean of its divisors is an integer number (1367157159936).

Almost surely, 2^{21103121210321} is an apocalyptic number.

It is an amenable number.

21103121210321 is a deficient number, since it is larger than the sum of its proper divisors (771393348655).

21103121210321 is a wasteful number, since it uses less digits than its factorization.

21103121210321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219868.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 21103121210321 its reverse (12301212130112), we get a palindrome (33404333340433).

The spelling of 21103121210321 in words is "twenty-one trillion, one hundred three billion, one hundred twenty-one million, two hundred ten thousand, three hundred twenty-one".