209764836 has 96 divisors (see below), whose sum is σ = 589438080. Its totient is φ = 64253952.

The previous prime is 209764799. The next prime is 209764837. The reversal of 209764836 is 638467902.

It is a junction number, because it is equal to n+sod(n) for n = 209764791 and 209764800.

It is not an unprimeable number, because it can be changed into a prime (209764837) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77620 + ... + 80276.

It is an arithmetic number, because the mean of its divisors is an integer number (6139980).

Almost surely, 2^209764836 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 209764836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294719040).

209764836 is an abundant number, since it is smaller than the sum of its proper divisors (379673244).

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

209764836 is a wasteful number, since it uses less digits than its factorization.

209764836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2730 (or 2722 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 209764836 is about 14483.2605445045. The cubic root of 209764836 is about 594.1702399507.

The spelling of 209764836 in words is "two hundred nine million, seven hundred sixty-four thousand, eight hundred thirty-six".