20213217 has 12 divisors (see below), whose sum is σ = 29362320. Its totient is φ = 13399128.

The previous prime is 20213197. The next prime is 20213233. The reversal of 20213217 is 71231202.

It is not a de Polignac number, because 20213217 - 2¹² = 20209121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20213217.

It is not an unprimeable number, because it can be changed into a prime (20213257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4663 + ... + 7884.

It is an arithmetic number, because the mean of its divisors is an integer number (2446860).

Almost surely, 2^20213217 is an apocalyptic number.

It is an amenable number.

20213217 is a deficient number, since it is larger than the sum of its proper divisors (9149103).

20213217 is a wasteful number, since it uses less digits than its factorization.

20213217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12732 (or 12729 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 20213217 is about 4495.9111423604. The cubic root of 20213217 is about 272.4029539680.

Adding to 20213217 its reverse (71231202), we get a palindrome (91444419).

The spelling of 20213217 in words is "twenty million, two hundred thirteen thousand, two hundred seventeen".