216765 has 12 divisors (see below), whose sum is σ = 375804. Its totient is φ = 115584.

The previous prime is 216761. The next prime is 216779. The reversal of 216765 is 567612.

It can be written as a sum of positive squares in 2 ways, for example, as 45369 + 171396 = 213^2 + 414^2 .

It is not a de Polignac number, because 216765 - 2² = 216761 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216765.

It is not an unprimeable number, because it can be changed into a prime (216761) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2364 + ... + 2453.

It is an arithmetic number, because the mean of its divisors is an integer number (31317).

2²¹⁶⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

216765 is a deficient number, since it is larger than the sum of its proper divisors (159039).

216765 is a wasteful number, since it uses less digits than its factorization.

216765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4828 (or 4825 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 216765 is about 465.5802830877. The cubic root of 216765 is about 60.0707498748.

It can be divided in two parts, 21 and 6765, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 216765 in words is "two hundred sixteen thousand, seven hundred sixty-five".