209845240 has 32 divisors (see below), whose sum is σ = 515075760. Its totient is φ = 76307200.

The previous prime is 209845219. The next prime is 209845243. The reversal of 209845240 is 42548902.

It is a junction number, because it is equal to n+sod(n) for n = 209845196 and 209845205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209845243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 238021 + ... + 238900.

Almost surely, 2^209845240 is an apocalyptic number.

209845240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209845240 is an abundant number, since it is smaller than the sum of its proper divisors (305230520).

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

209845240 is a wasteful number, since it uses less digits than its factorization.

209845240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476943 (or 476939 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 209845240 is about 14486.0360347474. The cubic root of 209845240 is about 594.2461464789.

The spelling of 209845240 in words is "two hundred nine million, eight hundred forty-five thousand, two hundred forty".