209835140 has 48 divisors (see below), whose sum is σ = 454879152. Its totient is φ = 81248256.

The previous prime is 209835113. The next prime is 209835163. The reversal of 209835140 is 41538902.

It can be written as a sum of positive squares in 8 ways, for example, as 1552516 + 208282624 = 1246^2 + 14432^2 .

It is a junction number, because it is equal to n+sod(n) for n = 209835097 and 209835106.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171812 + ... + 173028.

It is an arithmetic number, because the mean of its divisors is an integer number (9476649).

Almost surely, 2^209835140 is an apocalyptic number.

209835140 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 209835140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227439576).

209835140 is an abundant number, since it is smaller than the sum of its proper divisors (245044012).

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

209835140 is a wasteful number, since it uses less digits than its factorization.

209835140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1496 (or 1494 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 209835140 is about 14485.6874189664. The cubic root of 209835140 is about 594.2366124967.

The spelling of 209835140 in words is "two hundred nine million, eight hundred thirty-five thousand, one hundred forty".