20217243 has 8 divisors (see below), whose sum is σ = 26993728. Its totient is φ = 13459464.

The previous prime is 20217229. The next prime is 20217259. The reversal of 20217243 is 34271202.

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

It is not a de Polignac number, because 20217243 - 2¹⁶ = 20151707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20217283) 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, 1921 + ... + 6642.

It is an arithmetic number, because the mean of its divisors is an integer number (3374216).

Almost surely, 2^20217243 is an apocalyptic number.

20217243 is a deficient number, since it is larger than the sum of its proper divisors (6776485).

20217243 is an equidigital number, since it uses as much as digits as its factorization.

20217243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9353.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 20217243 is about 4496.3588602335. The cubic root of 20217243 is about 272.4210381995.

Adding to 20217243 its reverse (34271202), we get a palindrome (54488445).

The spelling of 20217243 in words is "twenty million, two hundred seventeen thousand, two hundred forty-three".