19809966 has 16 divisors (see below), whose sum is σ = 43221888. Its totient is φ = 6003000.

The previous prime is 19809953. The next prime is 19809973. The reversal of 19809966 is 66990891.

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, 150010 + ... + 150141.

It is an arithmetic number, because the mean of its divisors is an integer number (2701368).

Almost surely, 2^19809966 is an apocalyptic number.

19809966 is an abundant number, since it is smaller than the sum of its proper divisors (23411922).

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

19809966 is a wasteful number, since it uses less digits than its factorization.

19809966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300167.

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

The square root of 19809966 is about 4450.8387973504. The cubic root of 19809966 is about 270.5793048667.

The spelling of 19809966 in words is "nineteen million, eight hundred nine thousand, nine hundred sixty-six".