19864213 has 4 divisors (see below), whose sum is σ = 20348748. Its totient is φ = 19379680.

The previous prime is 19864193. The next prime is 19864219. The reversal of 19864213 is 31246891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5673924 + 14190289 = 2382^2 + 3767^2 .

It is a cyclic number.

It is not a de Polignac number, because 19864213 - 2⁵ = 19864181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19864219) 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 3 ways as a sum of consecutive naturals, for example, 242206 + ... + 242287.

It is an arithmetic number, because the mean of its divisors is an integer number (5087187).

Almost surely, 2^19864213 is an apocalyptic number.

It is an amenable number.

19864213 is a deficient number, since it is larger than the sum of its proper divisors (484535).

19864213 is an equidigital number, since it uses as much as digits as its factorization.

19864213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484534.

The product of its digits is 10368, while the sum is 34.

The square root of 19864213 is about 4456.9286509883. The cubic root of 19864213 is about 270.8260617745.

The spelling of 19864213 in words is "nineteen million, eight hundred sixty-four thousand, two hundred thirteen".