19868109 has 4 divisors (see below), whose sum is σ = 26490816. Its totient is φ = 13245404.

The previous prime is 19868099. The next prime is 19868111. The reversal of 19868109 is 90186891.

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 19868109 - 2⁵ = 19868077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19861109) 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, 3311349 + ... + 3311354.

It is an arithmetic number, because the mean of its divisors is an integer number (6622704).

Almost surely, 2^19868109 is an apocalyptic number.

It is an amenable number.

19868109 is a deficient number, since it is larger than the sum of its proper divisors (6622707).

19868109 is an equidigital number, since it uses as much as digits as its factorization.

19868109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6622706.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 19868109 is about 4457.3657018468. The cubic root of 19868109 is about 270.8437664673.

It can be divided in two parts, 19868 and 109, that multiplied together give a palindrome (2165612).

The spelling of 19868109 in words is "nineteen million, eight hundred sixty-eight thousand, one hundred nine".