261677 has 4 divisors (see below), whose sum is σ = 281820. Its totient is φ = 241536.

The previous prime is 261673. The next prime is 261697. The reversal of 261677 is 776162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 776162 = 2 ⋅388081.

It can be written as a sum of positive squares in 2 ways, for example, as 139876 + 121801 = 374^2 + 349^2 .

It is a cyclic number.

It is not a de Polignac number, because 261677 - 2² = 261673 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261677.

It is not an unprimeable number, because it can be changed into a prime (261673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10052 + ... + 10077.

It is an arithmetic number, because the mean of its divisors is an integer number (70455).

2²⁶¹⁶⁷⁷ is an apocalyptic number.

It is an amenable number.

261677 is a deficient number, since it is larger than the sum of its proper divisors (20143).

261677 is a wasteful number, since it uses less digits than its factorization.

261677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20142.

The product of its digits is 3528, while the sum is 29.

The square root of 261677 is about 511.5437420202. The cubic root of 261677 is about 63.9619728524.

The spelling of 261677 in words is "two hundred sixty-one thousand, six hundred seventy-seven".