20840217 has 8 divisors (see below), whose sum is σ = 27810720. Its totient is φ = 13881600.

The previous prime is 20840173. The next prime is 20840233. The reversal of 20840217 is 71204802.

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

It is not a de Polignac number, because 20840217 - 2⁸ = 20839961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20840297) 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 7 ways as a sum of consecutive naturals, for example, 2634 + ... + 6972.

It is an arithmetic number, because the mean of its divisors is an integer number (3476340).

Almost surely, 2^20840217 is an apocalyptic number.

It is an amenable number.

20840217 is a deficient number, since it is larger than the sum of its proper divisors (6970503).

20840217 is a wasteful number, since it uses less digits than its factorization.

20840217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5943.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20840217 is about 4565.1086515000. The cubic root of 20840217 is about 275.1909065594.

The spelling of 20840217 in words is "twenty million, eight hundred forty thousand, two hundred seventeen".