243986 has 4 divisors (see below), whose sum is σ = 365982. Its totient is φ = 121992.

The previous prime is 243973. The next prime is 243989. The reversal of 243986 is 689342.

243986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689342 = 2 ⋅344671.

It can be written as a sum of positive squares in only one way, i.e., 219961 + 24025 = 469^2 + 155^2 .

It is a d-powerful number, because it can be written as 2 + 4 + 9⁵ + 3¹¹ + 8 + 6⁵ .

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 243986.

It is not an unprimeable number, because it can be changed into a prime (243989) by changing a digit.

243986 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60995 + ... + 60998.

2²⁴³⁹⁸⁶ is an apocalyptic number.

243986 is a deficient number, since it is larger than the sum of its proper divisors (121996).

243986 is a wasteful number, since it uses less digits than its factorization.

243986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121995.

The product of its digits is 10368, while the sum is 32.

The square root of 243986 is about 493.9493901201. The cubic root of 243986 is about 62.4868025468.

The spelling of 243986 in words is "two hundred forty-three thousand, nine hundred eighty-six".