21165330999 has 4 divisors (see below), whose sum is σ = 28220441336. Its totient is φ = 14110220664.

The previous prime is 21165330997. The next prime is 21165331049. The reversal of 21165330999 is 99903356112.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21165330999 - 2¹ = 21165330997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21165330997) 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 3 ways as a sum of consecutive naturals, for example, 3527555164 + ... + 3527555169.

It is an arithmetic number, because the mean of its divisors is an integer number (7055110334).

Almost surely, 2^21165330999 is an apocalyptic number.

21165330999 is a deficient number, since it is larger than the sum of its proper divisors (7055110337).

21165330999 is an equidigital number, since it uses as much as digits as its factorization.

21165330999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7055110336.

The product of its (nonzero) digits is 393660, while the sum is 48.

The spelling of 21165330999 in words is "twenty-one billion, one hundred sixty-five million, three hundred thirty thousand, nine hundred ninety-nine".