261071617 has 4 divisors (see below), whose sum is σ = 261475776. Its totient is φ = 260667460.

The previous prime is 261071611. The next prime is 261071633. The reversal of 261071617 is 716170162.

261071617 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 261071617 - 2²³ = 252683009 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261071611) 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, 201109 + ... + 202402.

It is an arithmetic number, because the mean of its divisors is an integer number (65368944).

Almost surely, 2^261071617 is an apocalyptic number.

It is an amenable number.

261071617 is a deficient number, since it is larger than the sum of its proper divisors (404159).

261071617 is an equidigital number, since it uses as much as digits as its factorization.

261071617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404158.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 261071617 is about 16157.7107598818. The cubic root of 261071617 is about 639.1260997397.

The spelling of 261071617 in words is "two hundred sixty-one million, seventy-one thousand, six hundred seventeen".