261242 has 4 divisors (see below), whose sum is σ = 391866. Its totient is φ = 130620.

The previous prime is 261241. The next prime is 261251. The reversal of 261242 is 242162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242162 = 2 ⋅121081.

It can be written as a sum of positive squares in only one way, i.e., 261121 + 121 = 511^2 + 11^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 261242.

It is not an unprimeable number, because it can be changed into a prime (261241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65309 + ... + 65312.

2²⁶¹²⁴² is an apocalyptic number.

261242 is a deficient number, since it is larger than the sum of its proper divisors (130624).

261242 is a wasteful number, since it uses less digits than its factorization.

261242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130623.

The product of its digits is 192, while the sum is 17.

The square root of 261242 is about 511.1183815908. The cubic root of 261242 is about 63.9265106988.

The spelling of 261242 in words is "two hundred sixty-one thousand, two hundred forty-two".