19906986 has 32 divisors (see below), whose sum is σ = 43934400. Its totient is φ = 5962880.

The previous prime is 19906981. The next prime is 19906993. The reversal of 19906986 is 68960991.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19906981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4180 + ... + 7568.

It is an arithmetic number, because the mean of its divisors is an integer number (1372950).

Almost surely, 2^19906986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19906986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21967200).

19906986 is an abundant number, since it is smaller than the sum of its proper divisors (24027414).

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

19906986 is a wasteful number, since it uses less digits than its factorization.

19906986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3494.

The product of its (nonzero) digits is 209952, while the sum is 48.

The square root of 19906986 is about 4461.7245544744. The cubic root of 19906986 is about 271.0203095666.

The spelling of 19906986 in words is "nineteen million, nine hundred six thousand, nine hundred eighty-six".