19888161 has 4 divisors (see below), whose sum is σ = 26517552. Its totient is φ = 13258772.

The previous prime is 19888111. The next prime is 19888177. The reversal of 19888161 is 16188891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19888161 - 2²¹ = 17791009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19888111) 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, 3314691 + ... + 3314696.

It is an arithmetic number, because the mean of its divisors is an integer number (6629388).

Almost surely, 2^19888161 is an apocalyptic number.

It is an amenable number.

19888161 is a deficient number, since it is larger than the sum of its proper divisors (6629391).

19888161 is an equidigital number, since it uses as much as digits as its factorization.

19888161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6629390.

The product of its digits is 27648, while the sum is 42.

The square root of 19888161 is about 4459.6144452183. The cubic root of 19888161 is about 270.9348526925.

The spelling of 19888161 in words is "nineteen million, eight hundred eighty-eight thousand, one hundred sixty-one".