209017872 has 120 divisors (see below), whose sum is σ = 690193920. Its totient is φ = 57784320.

The previous prime is 209017817. The next prime is 209017891. The reversal of 209017872 is 278710902.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27904 + ... + 34592.

It is an arithmetic number, because the mean of its divisors is an integer number (5751616).

Almost surely, 2^209017872 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 209017872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345096960).

209017872 is an abundant number, since it is smaller than the sum of its proper divisors (481176048).

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

209017872 is a wasteful number, since it uses less digits than its factorization.

209017872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6741 (or 6732 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 209017872 is about 14457.4503976324. The cubic root of 209017872 is about 593.4641291697.

The spelling of 209017872 in words is "two hundred nine million, seventeen thousand, eight hundred seventy-two".