261155562593 has 2 divisors, whose sum is σ = 261155562594. Its totient is φ = 261155562592.

The previous prime is 261155562581. The next prime is 261155562601. The reversal of 261155562593 is 395265551162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157286007649 + 103869554944 = 396593^2 + 322288^2 .

It is a cyclic number.

It is not a de Polignac number, because 261155562593 - 2⁶ = 261155562529 is a prime.

It is not a weakly prime, because it can be changed into another prime (261155562523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130577781296 + 130577781297.

It is an arithmetic number, because the mean of its divisors is an integer number (130577781297).

Almost surely, 2^261155562593 is an apocalyptic number.

It is an amenable number.

261155562593 is a deficient number, since it is larger than the sum of its proper divisors (1).

261155562593 is an equidigital number, since it uses as much as digits as its factorization.

261155562593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2430000, while the sum is 50.

The spelling of 261155562593 in words is "two hundred sixty-one billion, one hundred fifty-five million, five hundred sixty-two thousand, five hundred ninety-three".