261971 has 2 divisors, whose sum is σ = 261972. Its totient is φ = 261970.

The previous prime is 261959. The next prime is 261973. The reversal of 261971 is 179162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261971 - 2¹⁴ = 245587 is a prime.

Together with 261973, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261971.

It is not a weakly prime, because it can be changed into another prime (261973) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130985 + 130986.

It is an arithmetic number, because the mean of its divisors is an integer number (130986).

2²⁶¹⁹⁷¹ is an apocalyptic number.

261971 is a deficient number, since it is larger than the sum of its proper divisors (1).

261971 is an equidigital number, since it uses as much as digits as its factorization.

261971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 26.

The square root of 261971 is about 511.8310268047. The cubic root of 261971 is about 63.9859181258.

The spelling of 261971 in words is "two hundred sixty-one thousand, nine hundred seventy-one".