217112240 has 40 divisors (see below), whose sum is σ = 531357360. Its totient is φ = 82273536.

The previous prime is 217112213. The next prime is 217112243. The reversal of 217112240 is 42211712.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (217112243) 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, 69899 + ... + 72938.

It is an arithmetic number, because the mean of its divisors is an integer number (13283934).

Almost surely, 2^217112240 is an apocalyptic number.

217112240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217112240 is an abundant number, since it is smaller than the sum of its proper divisors (314245120).

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

217112240 is a wasteful number, since it uses less digits than its factorization.

217112240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142869 (or 142863 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 217112240 is about 14734.7290439967. The cubic root of 217112240 is about 601.0280892332.

Adding to 217112240 its reverse (42211712), we get a palindrome (259323952).

The spelling of 217112240 in words is "two hundred seventeen million, one hundred twelve thousand, two hundred forty".