21120090209 has 8 divisors (see below), whose sum is σ = 21477462720. Its totient is φ = 20763957456.

The previous prime is 21120090169. The next prime is 21120090263. The reversal of 21120090209 is 90209002112.

It is a happy number.

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 21120090209 - 2²⁸ = 20851654753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120093209) 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, 275549 + ... + 343754.

It is an arithmetic number, because the mean of its divisors is an integer number (2684682840).

Almost surely, 2^21120090209 is an apocalyptic number.

It is an amenable number.

21120090209 is a deficient number, since it is larger than the sum of its proper divisors (357372511).

21120090209 is an equidigital number, since it uses as much as digits as its factorization.

21120090209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619879.

The product of its (nonzero) digits is 648, while the sum is 26.

The spelling of 21120090209 in words is "twenty-one billion, one hundred twenty million, ninety thousand, two hundred nine".