261197 has 4 divisors (see below), whose sum is σ = 263100. Its totient is φ = 259296.

The previous prime is 261169. The next prime is 261223. The reversal of 261197 is 791162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 791162 = 2 ⋅395581.

It can be written as a sum of positive squares in 2 ways, for example, as 17161 + 244036 = 131^2 + 494^2 .

It is a cyclic number.

It is not a de Polignac number, because 261197 - 2⁸ = 260941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 728 + ... + 1025.

It is an arithmetic number, because the mean of its divisors is an integer number (65775).

2²⁶¹¹⁹⁷ is an apocalyptic number.

It is an amenable number.

261197 is a deficient number, since it is larger than the sum of its proper divisors (1903).

261197 is a wasteful number, since it uses less digits than its factorization.

261197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1902.

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

The square root of 261197 is about 511.0743585820. The cubic root of 261197 is about 63.9228399540.

The spelling of 261197 in words is "two hundred sixty-one thousand, one hundred ninety-seven".