19938013 has 4 divisors (see below), whose sum is σ = 20424348. Its totient is φ = 19451680.

The previous prime is 19938001. The next prime is 19938029. The reversal of 19938013 is 31083991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31083991 = 3371 ⋅9221.

It can be written as a sum of positive squares in 2 ways, for example, as 11539609 + 8398404 = 3397^2 + 2898^2 .

It is a cyclic number.

It is not a de Polignac number, because 19938013 - 2¹³ = 19929821 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19938013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19938073) 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, 243106 + ... + 243187.

It is an arithmetic number, because the mean of its divisors is an integer number (5106087).

Almost surely, 2^19938013 is an apocalyptic number.

It is an amenable number.

19938013 is a deficient number, since it is larger than the sum of its proper divisors (486335).

19938013 is an equidigital number, since it uses as much as digits as its factorization.

19938013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486334.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 19938013 is about 4465.2002194750. The cubic root of 19938013 is about 271.1610404337.

The spelling of 19938013 in words is "nineteen million, nine hundred thirty-eight thousand, thirteen".