209668634 has 16 divisors (see below), whose sum is σ = 361815936. Its totient is φ = 89262000.

The previous prime is 209668631. The next prime is 209668639. The reversal of 209668634 is 436866902.

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 not an unprimeable number, because it can be changed into a prime (209668631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47477 + ... + 51704.

It is an arithmetic number, because the mean of its divisors is an integer number (22613496).

Almost surely, 2^209668634 is an apocalyptic number.

209668634 is a deficient number, since it is larger than the sum of its proper divisors (152147302).

209668634 is a wasteful number, since it uses less digits than its factorization.

209668634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99341.

The product of its (nonzero) digits is 373248, while the sum is 44.

The square root of 209668634 is about 14479.9390192086. The cubic root of 209668634 is about 594.0793936058.

The spelling of 209668634 in words is "two hundred nine million, six hundred sixty-eight thousand, six hundred thirty-four".