261669013 has 2 divisors, whose sum is σ = 261669014. Its totient is φ = 261669012.

The previous prime is 261668983. The next prime is 261669017. The reversal of 261669013 is 310966162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 238609809 + 23059204 = 15447^2 + 4802^2 .

It is a cyclic number.

It is not a de Polignac number, because 261669013 - 2⁹ = 261668501 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261669013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261669017) 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, 130834506 + 130834507.

It is an arithmetic number, because the mean of its divisors is an integer number (130834507).

Almost surely, 2^261669013 is an apocalyptic number.

It is an amenable number.

261669013 is a deficient number, since it is larger than the sum of its proper divisors (1).

261669013 is an equidigital number, since it uses as much as digits as its factorization.

261669013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 261669013 is about 16176.1866025340. The cubic root of 261669013 is about 639.6132208899.

The spelling of 261669013 in words is "two hundred sixty-one million, six hundred sixty-nine thousand, thirteen".