19688881 has 4 divisors (see below), whose sum is σ = 19740672. Its totient is φ = 19637092.

The previous prime is 19688869. The next prime is 19688887. The reversal of 19688881 is 18888691.

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 19688881 - 2⁹ = 19688369 is a prime.

It is a super-2 number, since 2×19688881² = 775304070064322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19688887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25321 + ... + 26086.

It is an arithmetic number, because the mean of its divisors is an integer number (4935168).

Almost surely, 2^19688881 is an apocalyptic number.

It is an amenable number.

19688881 is a deficient number, since it is larger than the sum of its proper divisors (51791).

19688881 is an equidigital number, since it uses as much as digits as its factorization.

19688881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51790.

The product of its digits is 221184, while the sum is 49.

The square root of 19688881 is about 4437.2154556659. The cubic root of 19688881 is about 270.0268880401.

It can be divided in two parts, 19 and 688881, that added together give a square (688900 = 830²).

The spelling of 19688881 in words is "nineteen million, six hundred eighty-eight thousand, eight hundred eighty-one".