19820217 has 4 divisors (see below), whose sum is σ = 26426960. Its totient is φ = 13213476.

The previous prime is 19820167. The next prime is 19820219. The reversal of 19820217 is 71202891.

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, and also an emirpimes, since its reverse is a distinct semiprime: 71202891 = 3 ⋅23734297.

It is not a de Polignac number, because 19820217 - 2⁶ = 19820153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19820219) 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, 3303367 + ... + 3303372.

It is an arithmetic number, because the mean of its divisors is an integer number (6606740).

Almost surely, 2^19820217 is an apocalyptic number.

It is an amenable number.

19820217 is a deficient number, since it is larger than the sum of its proper divisors (6606743).

19820217 is an equidigital number, since it uses as much as digits as its factorization.

19820217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6606742.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 19820217 is about 4451.9902290998. The cubic root of 19820217 is about 270.6259687556.

The spelling of 19820217 in words is "nineteen million, eight hundred twenty thousand, two hundred seventeen".