21031023321 has 24 divisors (see below), whose sum is σ = 37874051904. Its totient is φ = 10925206560.

The previous prime is 21031023311. The next prime is 21031023331. The reversal of 21031023321 is 12332013012.

21031023321 is a `hidden beast` number, since 2 + 10 + 310 + 23 + 321 = 666.

It is an interprime number because it is at equal distance from previous prime (21031023311) and next prime (21031023331).

It is not a de Polignac number, because 21031023321 - 2¹⁰ = 21031022297 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21031023294 and 21031023303.

It is not an unprimeable number, because it can be changed into a prime (21031023311) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15173206 + ... + 15174591.

It is an arithmetic number, because the mean of its divisors is an integer number (1578085496).

Almost surely, 2^21031023321 is an apocalyptic number.

21031023321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21031023321 is a deficient number, since it is larger than the sum of its proper divisors (16843028583).

21031023321 is a wasteful number, since it uses less digits than its factorization.

21031023321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30347821 (or 30347818 counting only the distinct ones).

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

Adding to 21031023321 its reverse (12332013012), we get a palindrome (33363036333).

The spelling of 21031023321 in words is "twenty-one billion, thirty-one million, twenty-three thousand, three hundred twenty-one".