21001022221209 has 32 divisors (see below), whose sum is σ = 29741135692800. Its totient is φ = 13144515278400.

The previous prime is 21001022221159. The next prime is 21001022221271. The reversal of 21001022221209 is 90212222010012.

It is not a de Polignac number, because 21001022221209 - 2¹² = 21001022217113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001023221209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 694647 + ... + 6518019.

It is an arithmetic number, because the mean of its divisors is an integer number (929410490400).

Almost surely, 2^{21001022221209} is an apocalyptic number.

It is an amenable number.

21001022221209 is a deficient number, since it is larger than the sum of its proper divisors (8740113471591).

21001022221209 is a wasteful number, since it uses less digits than its factorization.

21001022221209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5823965.

The product of its (nonzero) digits is 576, while the sum is 24.

The spelling of 21001022221209 in words is "twenty-one trillion, one billion, twenty-two million, two hundred twenty-one thousand, two hundred nine".