21112220999 has 4 divisors (see below), whose sum is σ = 21128132064. Its totient is φ = 21096309936.

The previous prime is 21112220993. The next prime is 21112221023. The reversal of 21112220999 is 99902221112.

It is a happy number.

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 21112220999 - 2²⁴ = 21095443783 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 (21112220993) 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, 7953542 + ... + 7956195.

It is an arithmetic number, because the mean of its divisors is an integer number (5282033016).

Almost surely, 2^21112220999 is an apocalyptic number.

21112220999 is a deficient number, since it is larger than the sum of its proper divisors (15911065).

21112220999 is a wasteful number, since it uses less digits than its factorization.

21112220999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15911064.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 21112220999 in words is "twenty-one billion, one hundred twelve million, two hundred twenty thousand, nine hundred ninety-nine".