19555009 has 8 divisors (see below), whose sum is σ = 20648480. Its totient is φ = 18519300.

The previous prime is 19555007. The next prime is 19555027. The reversal of 19555009 is 90055591.

It is not a de Polignac number, because 19555009 - 2¹ = 19555007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19555001) 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, 5434 + ... + 8284.

It is an arithmetic number, because the mean of its divisors is an integer number (2581060).

Almost surely, 2^19555009 is an apocalyptic number.

19555009 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19555009 is a deficient number, since it is larger than the sum of its proper divisors (1093471).

19555009 is an frugal number, since it uses more digits than its factorization.

19555009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2908 (or 2870 counting only the distinct ones).

The product of its (nonzero) digits is 10125, while the sum is 34.

The square root of 19555009 is about 4422.1045894461. The cubic root of 19555009 is about 269.4134913944.

The spelling of 19555009 in words is "nineteen million, five hundred fifty-five thousand, nine".