21213312999 has 4 divisors (see below), whose sum is σ = 28284417336. Its totient is φ = 14142208664.

The previous prime is 21213312917. The next prime is 21213313003. The reversal of 21213312999 is 99921331212.

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

It is a cyclic number.

It is not a de Polignac number, because 21213312999 - 2¹² = 21213308903 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21213312999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213312199) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3535552164 + ... + 3535552169.

It is an arithmetic number, because the mean of its divisors is an integer number (7071104334).

Almost surely, 2^21213312999 is an apocalyptic number.

21213312999 is a deficient number, since it is larger than the sum of its proper divisors (7071104337).

21213312999 is an equidigital number, since it uses as much as digits as its factorization.

21213312999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7071104336.

The product of its digits is 52488, while the sum is 42.

The spelling of 21213312999 in words is "twenty-one billion, two hundred thirteen million, three hundred twelve thousand, nine hundred ninety-nine".