261319847 has 4 divisors (see below), whose sum is σ = 261444720. Its totient is φ = 261194976.

The previous prime is 261319837. The next prime is 261319871. The reversal of 261319847 is 748913162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 748913162 = 2 ⋅374456581.

It is a cyclic number.

It is not a de Polignac number, because 261319847 - 2¹⁰ = 261318823 is a prime.

It is a super-2 number, since 2×261319847² = 136576124872206818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261319837) 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, 59243 + ... + 63500.

It is an arithmetic number, because the mean of its divisors is an integer number (65361180).

Almost surely, 2^261319847 is an apocalyptic number.

261319847 is a deficient number, since it is larger than the sum of its proper divisors (124873).

261319847 is a wasteful number, since it uses less digits than its factorization.

261319847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124872.

The product of its digits is 72576, while the sum is 41.

The square root of 261319847 is about 16165.3904066682. The cubic root of 261319847 is about 639.3285984742.

The spelling of 261319847 in words is "two hundred sixty-one million, three hundred nineteen thousand, eight hundred forty-seven".