19997844 has 12 divisors (see below), whose sum is σ = 46661664. Its totient is φ = 6665944.

The previous prime is 19997837. The next prime is 19997867. The reversal of 19997844 is 44879991.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 833232 + ... + 833255.

It is an arithmetic number, because the mean of its divisors is an integer number (3888472).

Almost surely, 2^19997844 is an apocalyptic number.

It is an amenable number.

19997844 is an abundant number, since it is smaller than the sum of its proper divisors (26663820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19997844 is a wasteful number, since it uses less digits than its factorization.

19997844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666494 (or 1666492 counting only the distinct ones).

The product of its digits is 653184, while the sum is 51.

The square root of 19997844 is about 4471.8949003750. The cubic root of 19997844 is about 271.4320075017.

The spelling of 19997844 in words is "nineteen million, nine hundred ninety-seven thousand, eight hundred forty-four".