261329539 has 2 divisors, whose sum is σ = 261329540. Its totient is φ = 261329538.

The previous prime is 261329507. The next prime is 261329569. The reversal of 261329539 is 935923162.

261329539 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261329539 - 2⁵ = 261329507 is a prime.

It is not a weakly prime, because it can be changed into another prime (261329569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130664769 + 130664770.

It is an arithmetic number, because the mean of its divisors is an integer number (130664770).

Almost surely, 2^261329539 is an apocalyptic number.

261329539 is a deficient number, since it is larger than the sum of its proper divisors (1).

261329539 is an equidigital number, since it uses as much as digits as its factorization.

261329539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 87480, while the sum is 40.

The square root of 261329539 is about 16165.6901801315. The cubic root of 261329539 is about 639.3365023210.

The spelling of 261329539 in words is "two hundred sixty-one million, three hundred twenty-nine thousand, five hundred thirty-nine".