19981116 has 36 divisors (see below), whose sum is σ = 52252200. Its totient is φ = 6430368.

The previous prime is 19981109. The next prime is 19981139. The reversal of 19981116 is 61118991.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8526 + ... + 10613.

It is an arithmetic number, because the mean of its divisors is an integer number (1451450).

Almost surely, 2^19981116 is an apocalyptic number.

It is an amenable number.

19981116 is an abundant number, since it is smaller than the sum of its proper divisors (32271084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19981116 is a wasteful number, since it uses less digits than its factorization.

19981116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19178 (or 19173 counting only the distinct ones).

The product of its digits is 3888, while the sum is 36.

The square root of 19981116 is about 4470.0241610085. The cubic root of 19981116 is about 271.3563029867.

The spelling of 19981116 in words is "nineteen million, nine hundred eighty-one thousand, one hundred sixteen".