217955 has 4 divisors (see below), whose sum is σ = 261552. Its totient is φ = 174360.

The previous prime is 217937. The next prime is 217969. The reversal of 217955 is 559712.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 217955 - 2¹² = 213859 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21791 + ... + 21800.

It is an arithmetic number, because the mean of its divisors is an integer number (65388).

2²¹⁷⁹⁵⁵ is an apocalyptic number.

217955 is a deficient number, since it is larger than the sum of its proper divisors (43597).

217955 is an equidigital number, since it uses as much as digits as its factorization.

217955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43596.

The product of its digits is 3150, while the sum is 29.

The square root of 217955 is about 466.8565090046. The cubic root of 217955 is about 60.1804751198.

The spelling of 217955 in words is "two hundred seventeen thousand, nine hundred fifty-five".