21140432321 has 2 divisors, whose sum is σ = 21140432322. Its totient is φ = 21140432320.

The previous prime is 21140432317. The next prime is 21140432333. The reversal of 21140432321 is 12323404112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19954387600 + 1186044721 = 141260^2 + 34439^2 .

It is a cyclic number.

It is not a de Polignac number, because 21140432321 - 2² = 21140432317 is a prime.

It is not a weakly prime, because it can be changed into another prime (21140432371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570216160 + 10570216161.

It is an arithmetic number, because the mean of its divisors is an integer number (10570216161).

Almost surely, 2^21140432321 is an apocalyptic number.

It is an amenable number.

21140432321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140432321 is an equidigital number, since it uses as much as digits as its factorization.

21140432321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21140432321 its reverse (12323404112), we get a palindrome (33463836433).

The spelling of 21140432321 in words is "twenty-one billion, one hundred forty million, four hundred thirty-two thousand, three hundred twenty-one".