261310993 has 2 divisors, whose sum is σ = 261310994. Its totient is φ = 261310992.

The previous prime is 261310969. The next prime is 261311077. The reversal of 261310993 is 399013162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196476289 + 64834704 = 14017^2 + 8052^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261310993 is a prime.

It is not a weakly prime, because it can be changed into another prime (261310943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130655496 + 130655497.

It is an arithmetic number, because the mean of its divisors is an integer number (130655497).

Almost surely, 2^261310993 is an apocalyptic number.

It is an amenable number.

261310993 is a deficient number, since it is larger than the sum of its proper divisors (1).

261310993 is an equidigital number, since it uses as much as digits as its factorization.

261310993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8748, while the sum is 34.

The square root of 261310993 is about 16165.1165476776. The cubic root of 261310993 is about 639.3213778473.

The spelling of 261310993 in words is "two hundred sixty-one million, three hundred ten thousand, nine hundred ninety-three".