209102100 has 72 divisors (see below), whose sum is σ = 613585728. Its totient is φ = 54969600.

The previous prime is 209102081. The next prime is 209102111. The reversal of 209102100 is 1201902.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 209102100.

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 23 ways as a sum of consecutive naturals, for example, 16392 + ... + 26208.

It is an arithmetic number, because the mean of its divisors is an integer number (8522024).

Almost surely, 2^209102100 is an apocalyptic number.

209102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209102100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306792864).

209102100 is an abundant number, since it is smaller than the sum of its proper divisors (404483628).

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

209102100 is a wasteful number, since it uses less digits than its factorization.

209102100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9905 (or 9898 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 209102100 is about 14460.3630659814. The cubic root of 209102100 is about 593.5438346088.

The spelling of 209102100 in words is "two hundred nine million, one hundred two thousand, one hundred".