217142755 has 12 divisors (see below), whose sum is σ = 269253936. Its totient is φ = 168106800.

The previous prime is 217142741. The next prime is 217142767. The reversal of 217142755 is 557241712.

It is a de Polignac number, because none of the positive numbers 2^k-217142755 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217142755.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17791 + ... + 27400.

It is an arithmetic number, because the mean of its divisors is an integer number (22437828).

Almost surely, 2^217142755 is an apocalyptic number.

217142755 is a deficient number, since it is larger than the sum of its proper divisors (52111181).

217142755 is an equidigital number, since it uses as much as digits as its factorization.

217142755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45258 (or 45227 counting only the distinct ones).

The product of its digits is 19600, while the sum is 34.

The square root of 217142755 is about 14735.7644864459. The cubic root of 217142755 is about 601.0562459645.

The spelling of 217142755 in words is "two hundred seventeen million, one hundred forty-two thousand, seven hundred fifty-five".