261855323 has 2 divisors, whose sum is σ = 261855324. Its totient is φ = 261855322.

The previous prime is 261855311. The next prime is 261855353. The reversal of 261855323 is 323558162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261855323 - 2¹⁸ = 261593179 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (261855353) 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, 130927661 + 130927662.

It is an arithmetic number, because the mean of its divisors is an integer number (130927662).

Almost surely, 2^261855323 is an apocalyptic number.

261855323 is a deficient number, since it is larger than the sum of its proper divisors (1).

261855323 is an equidigital number, since it uses as much as digits as its factorization.

261855323 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 35.

The square root of 261855323 is about 16181.9443516532. The cubic root of 261855323 is about 639.7649877685.

The spelling of 261855323 in words is "two hundred sixty-one million, eight hundred fifty-five thousand, three hundred twenty-three".