215965 has 8 divisors (see below), whose sum is σ = 264960. Its totient is φ = 168912.

The previous prime is 215959. The next prime is 215981. The reversal of 215965 is 569512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215965 is a prime.

215965 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 225 + ... + 694.

It is an arithmetic number, because the mean of its divisors is an integer number (33120).

2²¹⁵⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

215965 is a deficient number, since it is larger than the sum of its proper divisors (48995).

215965 is an equidigital number, since it uses as much as digits as its factorization.

215965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 971.

The product of its digits is 2700, while the sum is 28.

The square root of 215965 is about 464.7203460147. The cubic root of 215965 is about 59.9967590842.

The spelling of 215965 in words is "two hundred fifteen thousand, nine hundred sixty-five".