217542240 has 192 divisors, whose sum is σ = 782550720. Its totient is φ = 56401920.

The previous prime is 217542181. The next prime is 217542293. The reversal of 217542240 is 42245712.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159160 + ... + 160520.

It is an arithmetic number, because the mean of its divisors is an integer number (4075785).

Almost surely, 2^217542240 is an apocalyptic number.

217542240 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 217542240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391275360).

217542240 is an abundant number, since it is smaller than the sum of its proper divisors (565008480).

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

217542240 is a wasteful number, since it uses less digits than its factorization.

217542240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1422 (or 1408 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 27.

The square root of 217542240 is about 14749.3132043496. The cubic root of 217542240 is about 601.4246147774.

Adding to 217542240 its reverse (42245712), we get a palindrome (259787952).

The spelling of 217542240 in words is "two hundred seventeen million, five hundred forty-two thousand, two hundred forty".