19805089 has 4 divisors (see below), whose sum is σ = 19820224. Its totient is φ = 19789956.

The previous prime is 19805059. The next prime is 19805099. The reversal of 19805089 is 98050891.

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 19805089 - 2¹⁵ = 19772321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19805029) 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, 5397 + ... + 8290.

It is an arithmetic number, because the mean of its divisors is an integer number (4955056).

Almost surely, 2^19805089 is an apocalyptic number.

It is an amenable number.

19805089 is a deficient number, since it is larger than the sum of its proper divisors (15135).

19805089 is a wasteful number, since it uses less digits than its factorization.

19805089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15134.

The product of its (nonzero) digits is 25920, while the sum is 40.

The square root of 19805089 is about 4450.2908893689. The cubic root of 19805089 is about 270.5570984753.

The spelling of 19805089 in words is "nineteen million, eight hundred five thousand, eighty-nine".