209442240 has 224 divisors, whose sum is σ = 844661760. Its totient is φ = 47858688.

The previous prime is 209442197. The next prime is 209442241. The reversal of 209442240 is 42244902.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209442241) 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, 58749 + ... + 62211.

Almost surely, 2^209442240 is an apocalyptic number.

209442240 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 209442240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (422330880).

209442240 is an abundant number, since it is smaller than the sum of its proper divisors (635219520).

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

209442240 is a wasteful number, since it uses less digits than its factorization.

209442240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3496 (or 3480 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 209442240 is about 14472.1194024925. The cubic root of 209442240 is about 593.8654934705.

The spelling of 209442240 in words is "two hundred nine million, four hundred forty-two thousand, two hundred forty".