261330609 has 8 divisors (see below), whose sum is σ = 348516000. Its totient is φ = 174182816.

The previous prime is 261330599. The next prime is 261330659. The reversal of 261330609 is 906033162.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 261330609 - 2¹³ = 261322417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261330659) 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, 19642 + ... + 30140.

It is an arithmetic number, because the mean of its divisors is an integer number (43564500).

Almost surely, 2^261330609 is an apocalyptic number.

It is an amenable number.

261330609 is a deficient number, since it is larger than the sum of its proper divisors (87185391).

261330609 is a wasteful number, since it uses less digits than its factorization.

261330609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18799.

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 261330609 is about 16165.7232748801. The cubic root of 261330609 is about 639.3373748964.

The spelling of 261330609 in words is "two hundred sixty-one million, three hundred thirty thousand, six hundred nine".