19997648 has 20 divisors (see below), whose sum is σ = 42268128. Its totient is φ = 9089760.

The previous prime is 19997641. The next prime is 19997657. The reversal of 19997648 is 84679991.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 19997648.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56636 + ... + 56987.

Almost surely, 2^19997648 is an apocalyptic number.

It is an amenable number.

19997648 is an abundant number, since it is smaller than the sum of its proper divisors (22270480).

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

19997648 is a wasteful number, since it uses less digits than its factorization.

19997648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113642 (or 113636 counting only the distinct ones).

The product of its digits is 979776, while the sum is 53.

The square root of 19997648 is about 4471.8729856739. The cubic root of 19997648 is about 271.4311207253.

The spelling of 19997648 in words is "nineteen million, nine hundred ninety-seven thousand, six hundred forty-eight".