261686527 has 2 divisors, whose sum is σ = 261686528. Its totient is φ = 261686526.

The previous prime is 261686507. The next prime is 261686549. The reversal of 261686527 is 725686162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261686527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261686507) 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, 130843263 + 130843264.

It is an arithmetic number, because the mean of its divisors is an integer number (130843264).

Almost surely, 2^261686527 is an apocalyptic number.

261686527 is a deficient number, since it is larger than the sum of its proper divisors (1).

261686527 is an equidigital number, since it uses as much as digits as its factorization.

261686527 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 43.

The square root of 261686527 is about 16176.7279447977. The cubic root of 261686527 is about 639.6274907442.

The spelling of 261686527 in words is "two hundred sixty-one million, six hundred eighty-six thousand, five hundred twenty-seven".