261286971 has 16 divisors (see below), whose sum is σ = 380327808. Its totient is φ = 158241600.

The previous prime is 261286943. The next prime is 261287009. The reversal of 261286971 is 179682162.

It is not a de Polignac number, because 261286971 - 2²⁶ = 194178107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261286901) 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 15 ways as a sum of consecutive naturals, for example, 76776 + ... + 80106.

It is an arithmetic number, because the mean of its divisors is an integer number (23770488).

Almost surely, 2^261286971 is an apocalyptic number.

261286971 is a deficient number, since it is larger than the sum of its proper divisors (119040837).

261286971 is a wasteful number, since it uses less digits than its factorization.

261286971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5722.

The product of its digits is 72576, while the sum is 42.

The square root of 261286971 is about 16164.3735109035. The cubic root of 261286971 is about 639.3017865695.

The spelling of 261286971 in words is "two hundred sixty-one million, two hundred eighty-six thousand, nine hundred seventy-one".