209491982 has 16 divisors (see below), whose sum is σ = 364490880. Its totient is φ = 88441848.

The previous prime is 209491957. The next prime is 209491991. The reversal of 209491982 is 289194902.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 110732 + ... + 112607.

It is an arithmetic number, because the mean of its divisors is an integer number (22780680).

Almost surely, 2^209491982 is an apocalyptic number.

209491982 is a deficient number, since it is larger than the sum of its proper divisors (154998898).

209491982 is a wasteful number, since it uses less digits than its factorization.

209491982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223415.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 209491982 is about 14473.8378462659. The cubic root of 209491982 is about 593.9125035979.

The spelling of 209491982 in words is "two hundred nine million, four hundred ninety-one thousand, nine hundred eighty-two".