261534871 has 4 divisors (see below), whose sum is σ = 281652952. Its totient is φ = 241416792.

The previous prime is 261534853. The next prime is 261534899. The reversal of 261534871 is 178435162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261534871 - 2⁹ = 261534359 is a prime.

It is a super-4 number, since 4×261534871⁴ (a number of 35 digits) contains 4444 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261534871.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261534821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10059021 + ... + 10059046.

It is an arithmetic number, because the mean of its divisors is an integer number (70413238).

Almost surely, 2^261534871 is an apocalyptic number.

261534871 is a deficient number, since it is larger than the sum of its proper divisors (20118081).

261534871 is a wasteful number, since it uses less digits than its factorization.

261534871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20118080.

The product of its digits is 40320, while the sum is 37.

The square root of 261534871 is about 16172.0397909478. The cubic root of 261534871 is about 639.5039051030.

The spelling of 261534871 in words is "two hundred sixty-one million, five hundred thirty-four thousand, eight hundred seventy-one".