261285249 has 4 divisors (see below), whose sum is σ = 348380336. Its totient is φ = 174190164.

The previous prime is 261285247. The next prime is 261285259. The reversal of 261285249 is 942582162.

261285249 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 261285249 - 2¹ = 261285247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261285247) 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, 43547539 + ... + 43547544.

It is an arithmetic number, because the mean of its divisors is an integer number (87095084).

Almost surely, 2^261285249 is an apocalyptic number.

It is an amenable number.

261285249 is a deficient number, since it is larger than the sum of its proper divisors (87095087).

261285249 is an equidigital number, since it uses as much as digits as its factorization.

261285249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87095086.

The product of its digits is 69120, while the sum is 39.

The square root of 261285249 is about 16164.3202455284. The cubic root of 261285249 is about 639.3003821365.

The spelling of 261285249 in words is "two hundred sixty-one million, two hundred eighty-five thousand, two hundred forty-nine".