19985966 has 64 divisors (see below), whose sum is σ = 41126400. Its totient is φ = 7032960.

The previous prime is 19985963. The next prime is 19985969. The reversal of 19985966 is 66958991.

It is an interprime number because it is at equal distance from previous prime (19985963) and next prime (19985969).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19985963) 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 31 ways as a sum of consecutive naturals, for example, 134060 + ... + 134208.

It is an arithmetic number, because the mean of its divisors is an integer number (642600).

Almost surely, 2^19985966 is an apocalyptic number.

19985966 is an abundant number, since it is smaller than the sum of its proper divisors (21140434).

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

19985966 is a wasteful number, since it uses less digits than its factorization.

19985966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249.

The product of its digits is 1049760, while the sum is 53.

The square root of 19985966 is about 4470.5666307528. The cubic root of 19985966 is about 271.3782565753.

The spelling of 19985966 in words is "nineteen million, nine hundred eighty-five thousand, nine hundred sixty-six".