21030123321 has 12 divisors (see below), whose sum is σ = 30419698660. Its totient is φ = 14000303520.

The previous prime is 21030123319. The next prime is 21030123329. The reversal of 21030123321 is 12332103012.

21030123321 is a `hidden beast` number, since 21 + 0 + 301 + 23 + 321 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1364268096 + 19665855225 = 36936^2 + 140235^2 .

It is not a de Polignac number, because 21030123321 - 2¹ = 21030123319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21030123294 and 21030123303.

It is not an unprimeable number, because it can be changed into a prime (21030123329) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1641490 + ... + 1654251.

Almost surely, 2^21030123321 is an apocalyptic number.

It is an amenable number.

21030123321 is a deficient number, since it is larger than the sum of its proper divisors (9389575339).

21030123321 is a wasteful number, since it uses less digits than its factorization.

21030123321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3296456 (or 3296453 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21030123321 its reverse (12332103012), we get a palindrome (33362226333).

The spelling of 21030123321 in words is "twenty-one billion, thirty million, one hundred twenty-three thousand, three hundred twenty-one".