261704161 has 4 divisors (see below), whose sum is σ = 263309872. Its totient is φ = 260098452.

The previous prime is 261704159. The next prime is 261704167. The reversal of 261704161 is 161407162.

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 a cyclic number.

It is not a de Polignac number, because 261704161 - 2¹ = 261704159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261704167) 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, 802611 + ... + 802936.

It is an arithmetic number, because the mean of its divisors is an integer number (65827468).

Almost surely, 2^261704161 is an apocalyptic number.

It is an amenable number.

261704161 is a deficient number, since it is larger than the sum of its proper divisors (1605711).

261704161 is a wasteful number, since it uses less digits than its factorization.

261704161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1605710.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 261704161 is about 16177.2729778538. The cubic root of 261704161 is about 639.6418577274.

The spelling of 261704161 in words is "two hundred sixty-one million, seven hundred four thousand, one hundred sixty-one".