19889805 has 16 divisors (see below), whose sum is σ = 34272000. Its totient is φ = 9791808.

The previous prime is 19889803. The next prime is 19889833. The reversal of 19889805 is 50898891.

It is not a de Polignac number, because 19889805 - 2¹ = 19889803 is a prime.

It is a super-3 number, since 3×19889805³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19889801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50805 + ... + 51194.

It is an arithmetic number, because the mean of its divisors is an integer number (2142000).

Almost surely, 2^19889805 is an apocalyptic number.

19889805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19889805 is a deficient number, since it is larger than the sum of its proper divisors (14382195).

19889805 is a wasteful number, since it uses less digits than its factorization.

19889805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102020.

The product of its (nonzero) digits is 207360, while the sum is 48.

The square root of 19889805 is about 4459.7987622762. The cubic root of 19889805 is about 270.9423178477.

The spelling of 19889805 in words is "nineteen million, eight hundred eighty-nine thousand, eight hundred five".