19944813 has 48 divisors (see below), whose sum is σ = 33616320. Its totient is φ = 10450944.

The previous prime is 19944797. The next prime is 19944829. The reversal of 19944813 is 31844991.

It is an interprime number because it is at equal distance from previous prime (19944797) and next prime (19944829).

It is not a de Polignac number, because 19944813 - 2⁴ = 19944797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19944833) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 103245 + ... + 103437.

It is an arithmetic number, because the mean of its divisors is an integer number (700340).

Almost surely, 2^19944813 is an apocalyptic number.

It is an amenable number.

19944813 is a deficient number, since it is larger than the sum of its proper divisors (13671507).

19944813 is a wasteful number, since it uses less digits than its factorization.

19944813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266 (or 259 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 19944813 is about 4465.9615985810. The cubic root of 19944813 is about 271.1918640584.

The spelling of 19944813 in words is "nineteen million, nine hundred forty-four thousand, eight hundred thirteen".