19866812 has 24 divisors (see below), whose sum is σ = 42071904. Its totient is φ = 8013312.

The previous prime is 19866793. The next prime is 19866823. The reversal of 19866812 is 21866891.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 19866812.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 20393 + ... + 21344.

It is an arithmetic number, because the mean of its divisors is an integer number (1752996).

Almost surely, 2^19866812 is an apocalyptic number.

It is an amenable number.

19866812 is an abundant number, since it is smaller than the sum of its proper divisors (22205092).

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

19866812 is a wasteful number, since it uses less digits than its factorization.

19866812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41765 (or 41763 counting only the distinct ones).

The product of its digits is 41472, while the sum is 41.

The square root of 19866812 is about 4457.2202099515. The cubic root of 19866812 is about 270.8378727339.

The spelling of 19866812 in words is "nineteen million, eight hundred sixty-six thousand, eight hundred twelve".