20381217 has 4 divisors (see below), whose sum is σ = 27174960. Its totient is φ = 13587476.

The previous prime is 20381213. The next prime is 20381219. The reversal of 20381217 is 71218302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20381217 - 2² = 20381213 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20381213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3396867 + ... + 3396872.

It is an arithmetic number, because the mean of its divisors is an integer number (6793740).

Almost surely, 2^20381217 is an apocalyptic number.

It is an amenable number.

20381217 is a deficient number, since it is larger than the sum of its proper divisors (6793743).

20381217 is an equidigital number, since it uses as much as digits as its factorization.

20381217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6793742.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20381217 is about 4514.5561243604. The cubic root of 20381217 is about 273.1555554593.

Adding to 20381217 its reverse (71218302), we get a palindrome (91599519).

The spelling of 20381217 in words is "twenty million, three hundred eighty-one thousand, two hundred seventeen".