21782289209 has 16 divisors (see below), whose sum is σ = 22677304320. Its totient is φ = 20897130240.

The previous prime is 21782289169. The next prime is 21782289229. The reversal of 21782289209 is 90298228712.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21782289209 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21782289229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6573137 + ... + 6576449.

It is an arithmetic number, because the mean of its divisors is an integer number (1417331520).

Almost surely, 2^21782289209 is an apocalyptic number.

21782289209 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21782289209 is a deficient number, since it is larger than the sum of its proper divisors (895015111).

21782289209 is a wasteful number, since it uses less digits than its factorization.

21782289209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4720.

The product of its (nonzero) digits is 580608, while the sum is 50.

The spelling of 21782289209 in words is "twenty-one billion, seven hundred eighty-two million, two hundred eighty-nine thousand, two hundred nine".