21021120011209 has 8 divisors (see below), whose sum is σ = 21195833379840. Its totient is φ = 20846988052416.

The previous prime is 21021120011173. The next prime is 21021120011321. The reversal of 21021120011209 is 90211002112012.

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

It is a cyclic number.

It is not a de Polignac number, because 21021120011209 - 2⁹ = 21021120010697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21021120011209.

It is not an unprimeable number, because it can be changed into a prime (21021120011509) 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, 145279849 + ... + 145424470.

It is an arithmetic number, because the mean of its divisors is an integer number (2649479172480).

Almost surely, 2^{21021120011209} is an apocalyptic number.

It is an amenable number.

21021120011209 is a deficient number, since it is larger than the sum of its proper divisors (174713368631).

21021120011209 is a wasteful number, since it uses less digits than its factorization.

21021120011209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290704919.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 21021120011209 in words is "twenty-one trillion, twenty-one billion, one hundred twenty million, eleven thousand, two hundred nine".