19666944 has 144 divisors (see below), whose sum is σ = 62604360. Its totient is φ = 5898240.

The previous prime is 19666939. The next prime is 19666963. The reversal of 19666944 is 44966691.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 19666944.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 202704 + ... + 202800.

Almost surely, 2^19666944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19666944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31302180).

19666944 is an abundant number, since it is smaller than the sum of its proper divisors (42937416).

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

19666944 is a wasteful number, since it uses less digits than its factorization.

19666944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 113 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 19666944 is about 4434.7428335812. The cubic root of 19666944 is about 269.9265643907.

The spelling of 19666944 in words is "nineteen million, six hundred sixty-six thousand, nine hundred forty-four".