261779827 has 2 divisors, whose sum is σ = 261779828. Its totient is φ = 261779826.

The previous prime is 261779809. The next prime is 261779849. The reversal of 261779827 is 728977162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261779827 - 2²³ = 253391219 is a prime.

It is not a weakly prime, because it can be changed into another prime (261779857) 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, 130889913 + 130889914.

It is an arithmetic number, because the mean of its divisors is an integer number (130889914).

Almost surely, 2^261779827 is an apocalyptic number.

261779827 is a deficient number, since it is larger than the sum of its proper divisors (1).

261779827 is an equidigital number, since it uses as much as digits as its factorization.

261779827 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 592704, while the sum is 49.

The square root of 261779827 is about 16179.6114601062. The cubic root of 261779827 is about 639.7034979103.

The spelling of 261779827 in words is "two hundred sixty-one million, seven hundred seventy-nine thousand, eight hundred twenty-seven".