19908009 has 36 divisors (see below), whose sum is σ = 32097156. Its totient is φ = 11880000.

The previous prime is 19907999. The next prime is 19908017. The reversal of 19908009 is 90080991.

It can be written as a sum of positive squares in 2 ways, for example, as 9018009 + 10890000 = 3003^2 + 3300^2 .

It is not a de Polignac number, because 19908009 - 2¹¹ = 19905961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19908059) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 109899 + ... + 110079.

Almost surely, 2^19908009 is an apocalyptic number.

It is an amenable number.

19908009 is a deficient number, since it is larger than the sum of its proper divisors (12189147).

19908009 is a wasteful number, since it uses less digits than its factorization.

19908009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 296 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 19908009 is about 4461.8391947716. The cubic root of 19908009 is about 271.0249519742.

It can be divided in two parts, 1990 and 8009, that added together give a palindrome (9999).

The spelling of 19908009 in words is "nineteen million, nine hundred eight thousand, nine".