261699623 has 2 divisors, whose sum is σ = 261699624. Its totient is φ = 261699622.

The previous prime is 261699491. The next prime is 261699703. The reversal of 261699623 is 326996162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261699623 - 2⁸ = 261699367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261669623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130849811 + 130849812.

It is an arithmetic number, because the mean of its divisors is an integer number (130849812).

Almost surely, 2^261699623 is an apocalyptic number.

261699623 is a deficient number, since it is larger than the sum of its proper divisors (1).

261699623 is an equidigital number, since it uses as much as digits as its factorization.

261699623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 44.

The square root of 261699623 is about 16177.1327187484. The cubic root of 261699623 is about 639.6381605355.

The spelling of 261699623 in words is "two hundred sixty-one million, six hundred ninety-nine thousand, six hundred twenty-three".