209831028 has 96 divisors (see below), whose sum is σ = 551940480. Its totient is φ = 61501440.

The previous prime is 209831023. The next prime is 209831053. The reversal of 209831028 is 820138902.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 209831028.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209831023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 622476 + ... + 622812.

It is an arithmetic number, because the mean of its divisors is an integer number (5749380).

Almost surely, 2^209831028 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209831028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275970240).

209831028 is an abundant number, since it is smaller than the sum of its proper divisors (342109452).

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

209831028 is a wasteful number, since it uses less digits than its factorization.

209831028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497 (or 495 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 209831028 is about 14485.5454850689. The cubic root of 209831028 is about 594.2327308511.

The spelling of 209831028 in words is "two hundred nine million, eight hundred thirty-one thousand, twenty-eight".