261133809 has 16 divisors (see below), whose sum is σ = 355845312. Its totient is φ = 170276288.

The previous prime is 261133799. The next prime is 261133819. The reversal of 261133809 is 908331162.

It is an interprime number because it is at equal distance from previous prime (261133799) and next prime (261133819).

It is a cyclic number.

It is not a de Polignac number, because 261133809 - 2⁴ = 261133793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261133809.

It is not an unprimeable number, because it can be changed into a prime (261133819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52807 + ... + 57539.

It is an arithmetic number, because the mean of its divisors is an integer number (22240332).

Almost surely, 2^261133809 is an apocalyptic number.

It is an amenable number.

261133809 is a deficient number, since it is larger than the sum of its proper divisors (94711503).

261133809 is a wasteful number, since it uses less digits than its factorization.

261133809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5136.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 261133809 is about 16159.6351753373. The cubic root of 261133809 is about 639.1768461914.

The spelling of 261133809 in words is "two hundred sixty-one million, one hundred thirty-three thousand, eight hundred nine".