21131130321 has 24 divisors (see below), whose sum is σ = 34887213504. Its totient is φ = 12073520160.

The previous prime is 21131130287. The next prime is 21131130389. The reversal of 21131130321 is 12303113112.

21131130321 is a `hidden beast` number, since 2 + 1 + 1 + 311 + 30 + 321 = 666.

It is not a de Polignac number, because 21131130321 - 2¹⁰ = 21131129297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21131130294 and 21131130303.

It is not an unprimeable number, because it can be changed into a prime (21131130221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 781195 + ... + 807791.

It is an arithmetic number, because the mean of its divisors is an integer number (1453633896).

Almost surely, 2^21131130321 is an apocalyptic number.

21131130321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21131130321 is a deficient number, since it is larger than the sum of its proper divisors (13756083183).

21131130321 is a wasteful number, since it uses less digits than its factorization.

21131130321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39221 (or 39218 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21131130321 its reverse (12303113112), we get a palindrome (33434243433).

The spelling of 21131130321 in words is "twenty-one billion, one hundred thirty-one million, one hundred thirty thousand, three hundred twenty-one".