261825647 has 4 divisors (see below), whose sum is σ = 261878976. Its totient is φ = 261772320.

The previous prime is 261825623. The next prime is 261825649. The reversal of 261825647 is 746528162.

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

It is a cyclic number.

It is not a de Polignac number, because 261825647 - 2¹² = 261821551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261825649) 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, 18458 + ... + 29399.

It is an arithmetic number, because the mean of its divisors is an integer number (65469744).

Almost surely, 2^261825647 is an apocalyptic number.

261825647 is a deficient number, since it is larger than the sum of its proper divisors (53329).

261825647 is an equidigital number, since it uses as much as digits as its factorization.

261825647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53328.

The product of its digits is 161280, while the sum is 41.

The square root of 261825647 is about 16181.0273777656. The cubic root of 261825647 is about 639.7408187187.

The spelling of 261825647 in words is "two hundred sixty-one million, eight hundred twenty-five thousand, six hundred forty-seven".