19909917 has 12 divisors (see below), whose sum is σ = 28986880. Its totient is φ = 13168008.

The previous prime is 19909913. The next prime is 19909919. The reversal of 19909917 is 71990991.

It is not a de Polignac number, because 19909917 - 2² = 19909913 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19909913) 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, 7567 + ... + 9852.

Almost surely, 2^19909917 is an apocalyptic number.

It is an amenable number.

19909917 is a deficient number, since it is larger than the sum of its proper divisors (9076963).

19909917 is a wasteful number, since it uses less digits than its factorization.

19909917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17552 (or 17549 counting only the distinct ones).

The product of its (nonzero) digits is 45927, while the sum is 45.

The square root of 19909917 is about 4462.0530028228. The cubic root of 19909917 is about 271.0336101159.

The spelling of 19909917 in words is "nineteen million, nine hundred nine thousand, nine hundred seventeen".