243961 has 4 divisors (see below), whose sum is σ = 254592. Its totient is φ = 233332.

The previous prime is 243953. The next prime is 243973. The reversal of 243961 is 169342.

243961 = T₁₃₄ + T₁₃₅ + ... + T₁₅₆.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 243961 - 2³ = 243953 is a prime.

It is a d-powerful number, because it can be written as 2⁹ + 4⁸ + 9³ + 3¹¹ + 6² + 1 .

It is a Duffinian number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (243911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5281 + ... + 5326.

It is an arithmetic number, because the mean of its divisors is an integer number (63648).

2²⁴³⁹⁶¹ is an apocalyptic number.

It is an amenable number.

243961 is a deficient number, since it is larger than the sum of its proper divisors (10631).

243961 is a wasteful number, since it uses less digits than its factorization.

243961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10630.

The product of its digits is 1296, while the sum is 25.

The square root of 243961 is about 493.9240832355. The cubic root of 243961 is about 62.4846682393.

It can be divided in two parts, 2439 and 61, that added together give a square (2500 = 50²).

The spelling of 243961 in words is "two hundred forty-three thousand, nine hundred sixty-one".