261075245 has 4 divisors (see below), whose sum is σ = 313290300. Its totient is φ = 208860192.

The previous prime is 261075223. The next prime is 261075247. The reversal of 261075245 is 542570162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 163993636 + 97081609 = 12806^2 + 9853^2 .

It is a cyclic number.

It is not a de Polignac number, because 261075245 - 2¹⁶ = 261009709 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261075247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26107520 + ... + 26107529.

It is an arithmetic number, because the mean of its divisors is an integer number (78322575).

Almost surely, 2^261075245 is an apocalyptic number.

It is an amenable number.

261075245 is a deficient number, since it is larger than the sum of its proper divisors (52215055).

261075245 is an equidigital number, since it uses as much as digits as its factorization.

261075245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52215054.

The product of its (nonzero) digits is 16800, while the sum is 32.

The square root of 261075245 is about 16157.8230278711. The cubic root of 261075245 is about 639.1290602796.

The spelling of 261075245 in words is "two hundred sixty-one million, seventy-five thousand, two hundred forty-five".