19961109 has 24 divisors (see below), whose sum is σ = 33450560. Its totient is φ = 11233728.

The previous prime is 19961107. The next prime is 19961131. The reversal of 19961109 is 90116991.

It is not a de Polignac number, because 19961109 - 2¹ = 19961107 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19961101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1857 + ... + 6585.

Almost surely, 2^19961109 is an apocalyptic number.

It is an amenable number.

19961109 is a deficient number, since it is larger than the sum of its proper divisors (13489451).

19961109 is a wasteful number, since it uses less digits than its factorization.

19961109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4809 (or 4806 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 36.

The square root of 19961109 is about 4467.7856931594. The cubic root of 19961109 is about 271.2657034663.

The spelling of 19961109 in words is "nineteen million, nine hundred sixty-one thousand, one hundred nine".