19855009 has 8 divisors (see below), whose sum is σ = 20377728. Its totient is φ = 19336560.

The previous prime is 19855007. The next prime is 19855013. The reversal of 19855009 is 90055891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19855009 - 2¹ = 19855007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19855007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9739 + ... + 11599.

It is an arithmetic number, because the mean of its divisors is an integer number (2547216).

Almost surely, 2^19855009 is an apocalyptic number.

It is an amenable number.

19855009 is a deficient number, since it is larger than the sum of its proper divisors (522719).

19855009 is a wasteful number, since it uses less digits than its factorization.

19855009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135.

The product of its (nonzero) digits is 16200, while the sum is 37.

The square root of 19855009 is about 4455.8959817303. The cubic root of 19855009 is about 270.7842266049.

The spelling of 19855009 in words is "nineteen million, eight hundred fifty-five thousand, nine".