21123221009999 has 8 divisors (see below), whose sum is σ = 22336435121280. Its totient is φ = 19943245641600.

The previous prime is 21123221009977. The next prime is 21123221010029. The reversal of 21123221009999 is 99990012232112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123221009999 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 (21123221009909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8309684414 + ... + 8309686955.

It is an arithmetic number, because the mean of its divisors is an integer number (2792054390160).

Almost surely, 2^{21123221009999} is an apocalyptic number.

21123221009999 is a deficient number, since it is larger than the sum of its proper divisors (1213214111281).

21123221009999 is a wasteful number, since it uses less digits than its factorization.

21123221009999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16619371441.

The product of its (nonzero) digits is 314928, while the sum is 50.

The spelling of 21123221009999 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred twenty-one million, nine thousand, nine hundred ninety-nine".