198765 has 24 divisors (see below), whose sum is σ = 394368. Its totient is φ = 90720.

The previous prime is 198761. The next prime is 198769. The reversal of 198765 is 567891.

198765 is a nontrivial binomial coefficient, being equal to C(631, 2).

It is an interprime number because it is at equal distance from previous prime (198761) and next prime (198769).

It is not a de Polignac number, because 198765 - 2² = 198761 is a prime.

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 198765.

It is not an unprimeable number, because it can be changed into a prime (198761) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1 + ... + 630.

It is an arithmetic number, because the mean of its divisors is an integer number (16432).

2¹⁹⁸⁷⁶⁵ is an apocalyptic number.

198765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

198765 is the 630-th triangular number.

It is an amenable number.

198765 is a deficient number, since it is larger than the sum of its proper divisors (195603).

198765 is a wasteful number, since it uses less digits than its factorization.

198765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 646 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 198765 is about 445.8306853504. The cubic root of 198765 is about 58.3597340814.

It can be divided in two parts, 19876 and 5, that added together give a square (19881 = 141²).

The spelling of 198765 in words is "one hundred ninety-eight thousand, seven hundred sixty-five".