12765 has 16 divisors (see below), whose sum is σ = 21888. Its totient is φ = 6336.

The previous prime is 12763. The next prime is 12781. The reversal of 12765 is 56721.

It is not a de Polignac number, because 12765 - 2¹ = 12763 is a prime.

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

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 327 + ... + 363.

It is an arithmetic number, because the mean of its divisors is an integer number (1368).

2¹²⁷⁶⁵ is an apocalyptic number.

12765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12765 is a deficient number, since it is larger than the sum of its proper divisors (9123).

12765 is a wasteful number, since it uses less digits than its factorization.

12765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68.

The product of its digits is 420, while the sum is 21.

The square root of 12765 is about 112.9822994986. The cubic root of 12765 is about 23.3708014803.

Subtracting 12765 from its reverse (56721), we obtain a triangular number (43956 = T₂₉₆).

It can be divided in two parts, 12 and 765, that multiplied together give a triangular number (9180 = T₁₃₅).

The spelling of 12765 in words is "twelve thousand, seven hundred sixty-five".