261648609 has 8 divisors (see below), whose sum is σ = 348963552. Its totient is φ = 174383040.

The previous prime is 261648559. The next prime is 261648617. The reversal of 261648609 is 906846162.

261648609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261648609 - 2⁹ = 261648097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261648689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2614 + ... + 23024.

It is an arithmetic number, because the mean of its divisors is an integer number (43620444).

Almost surely, 2^261648609 is an apocalyptic number.

It is an amenable number.

261648609 is a deficient number, since it is larger than the sum of its proper divisors (87314943).

261648609 is a wasteful number, since it uses less digits than its factorization.

261648609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24687.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 261648609 is about 16175.5559100762. Note that the first 3 decimals coincide. The cubic root of 261648609 is about 639.5965955519.

The spelling of 261648609 in words is "two hundred sixty-one million, six hundred forty-eight thousand, six hundred nine".