209168828 has 18 divisors (see below), whose sum is σ = 402348408. Its totient is φ = 95076520.

The previous prime is 209168821. The next prime is 209168863. The reversal of 209168828 is 828861902.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209168821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 215600 + ... + 216567.

Almost surely, 2^209168828 is an apocalyptic number.

It is an amenable number.

209168828 is a deficient number, since it is larger than the sum of its proper divisors (193179580).

209168828 is a wasteful number, since it uses less digits than its factorization.

209168828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432193 (or 432180 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 44.

The square root of 209168828 is about 14462.6701545738. The cubic root of 209168828 is about 593.6069645037.

The spelling of 209168828 in words is "two hundred nine million, one hundred sixty-eight thousand, eight hundred twenty-eight".