261739 has 2 divisors, whose sum is σ = 261740. Its totient is φ = 261738.

The previous prime is 261721. The next prime is 261757. The reversal of 261739 is 937162.

It is a balanced prime because it is at equal distance from previous prime (261721) and next prime (261757).

It is a cyclic number.

It is not a de Polignac number, because 261739 - 2⁵ = 261707 is a prime.

It is not a weakly prime, because it can be changed into another prime (261799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130869 + 130870.

It is an arithmetic number, because the mean of its divisors is an integer number (130870).

2²⁶¹⁷³⁹ is an apocalyptic number.

261739 is a deficient number, since it is larger than the sum of its proper divisors (1).

261739 is an equidigital number, since it uses as much as digits as its factorization.

261739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 28.

The square root of 261739 is about 511.6043393092. The cubic root of 261739 is about 63.9670240277.

It can be divided in two parts, 261 and 739, that added together give a cube (1000 = 10³).

The spelling of 261739 in words is "two hundred sixty-one thousand, seven hundred thirty-nine".