261228594409 has 2 divisors, whose sum is σ = 261228594410. Its totient is φ = 261228594408.

The previous prime is 261228594377. The next prime is 261228594433. The reversal of 261228594409 is 904495822162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152199856384 + 109028738025 = 390128^2 + 330195^2 .

It is a cyclic number.

It is not a de Polignac number, because 261228594409 - 2⁵ = 261228594377 is a prime.

It is not a weakly prime, because it can be changed into another prime (261228594709) 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, 130614297204 + 130614297205.

It is an arithmetic number, because the mean of its divisors is an integer number (130614297205).

Almost surely, 2^261228594409 is an apocalyptic number.

It is an amenable number.

261228594409 is a deficient number, since it is larger than the sum of its proper divisors (1).

261228594409 is an equidigital number, since it uses as much as digits as its factorization.

261228594409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2488320, while the sum is 52.

The spelling of 261228594409 in words is "two hundred sixty-one billion, two hundred twenty-eight million, five hundred ninety-four thousand, four hundred nine".