19688885 has 4 divisors (see below), whose sum is σ = 23626668. Its totient is φ = 15751104.

The previous prime is 19688869. The next prime is 19688887. The reversal of 19688885 is 58888691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15437041 + 4251844 = 3929^2 + 2062^2 .

It is a cyclic number.

It is not a de Polignac number, because 19688885 - 2⁴ = 19688869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19688887) 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, 1968884 + ... + 1968893.

It is an arithmetic number, because the mean of its divisors is an integer number (5906667).

Almost surely, 2^19688885 is an apocalyptic number.

It is an amenable number.

19688885 is a deficient number, since it is larger than the sum of its proper divisors (3937783).

19688885 is an equidigital number, since it uses as much as digits as its factorization.

19688885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3937782.

The product of its digits is 1105920, while the sum is 53.

The square root of 19688885 is about 4437.2159063990. The cubic root of 19688885 is about 270.0269063264.

The spelling of 19688885 in words is "nineteen million, six hundred eighty-eight thousand, eight hundred eighty-five".