19916009 has 12 divisors (see below), whose sum is σ = 21524976. Its totient is φ = 18414648.

The previous prime is 19916003. The next prime is 19916021. The reversal of 19916009 is 90061991.

It is a de Polignac number, because none of the positive numbers 2^k-19916009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a zygodrome in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 19916009.

It is not an unprimeable number, because it can be changed into a prime (19916003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14882 + ... + 16164.

It is an arithmetic number, because the mean of its divisors is an integer number (1793748).

Almost surely, 2^19916009 is an apocalyptic number.

19916009 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19916009 is a deficient number, since it is larger than the sum of its proper divisors (1608967).

19916009 is a wasteful number, since it uses less digits than its factorization.

19916009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364 (or 1345 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 19916009 is about 4462.7355960218. The cubic root of 19916009 is about 271.0612507531.

It can be divided in two parts, 1991 and 6009, that added together give a cube (8000 = 20³).

The spelling of 19916009 in words is "nineteen million, nine hundred sixteen thousand, nine".