261001271 has 16 divisors (see below), whose sum is σ = 284000640. Its totient is φ = 239047200.

The previous prime is 261001267. The next prime is 261001277. The reversal of 261001271 is 172100162.

It is a cyclic number.

It is not a de Polignac number, because 261001271 - 2² = 261001267 is a prime.

It is a super-3 number, since 3×261001271³ (a number of 26 digits) contains 333 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 (261001277) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80936 + ... + 84098.

It is an arithmetic number, because the mean of its divisors is an integer number (17750040).

Almost surely, 2^261001271 is an apocalyptic number.

261001271 is a deficient number, since it is larger than the sum of its proper divisors (22999369).

261001271 is a wasteful number, since it uses less digits than its factorization.

261001271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3326.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 261001271 is about 16155.5337578181. The cubic root of 261001271 is about 639.0686902009.

The spelling of 261001271 in words is "two hundred sixty-one million, one thousand, two hundred seventy-one".