19991116 has 24 divisors (see below), whose sum is σ = 38994480. Its totient is φ = 8911872.

The previous prime is 19991107. The next prime is 19991129. The reversal of 19991116 is 61119991.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6445 + ... + 9028.

It is an arithmetic number, because the mean of its divisors is an integer number (1624770).

Almost surely, 2^19991116 is an apocalyptic number.

It is an amenable number.

19991116 is a deficient number, since it is larger than the sum of its proper divisors (19003364).

19991116 is a wasteful number, since it uses less digits than its factorization.

19991116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15513 (or 15511 counting only the distinct ones).

The product of its digits is 4374, while the sum is 37.

The square root of 19991116 is about 4471.1425832778. The cubic root of 19991116 is about 271.4015642302.

The spelling of 19991116 in words is "nineteen million, nine hundred ninety-one thousand, one hundred sixteen".