261439117 has 2 divisors, whose sum is σ = 261439118. Its totient is φ = 261439116.

The previous prime is 261439109. The next prime is 261439177. The reversal of 261439117 is 711934162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157276681 + 104162436 = 12541^2 + 10206^2 .

It is a cyclic number.

It is not a de Polignac number, because 261439117 - 2³ = 261439109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261439177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130719558 + 130719559.

It is an arithmetic number, because the mean of its divisors is an integer number (130719559).

Almost surely, 2^261439117 is an apocalyptic number.

It is an amenable number.

261439117 is a deficient number, since it is larger than the sum of its proper divisors (1).

261439117 is an equidigital number, since it uses as much as digits as its factorization.

261439117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 34.

The square root of 261439117 is about 16169.0790399453. The cubic root of 261439117 is about 639.4258498245.

The spelling of 261439117 in words is "two hundred sixty-one million, four hundred thirty-nine thousand, one hundred seventeen".