685486261 has 2 divisors, whose sum is σ = 685486262. Its totient is φ = 685486260.

The previous prime is 685486247. The next prime is 685486267. The reversal of 685486261 is 162684586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 494217361 + 191268900 = 22231^2 + 13830^2 .

It is a cyclic number.

It is not a de Polignac number, because 685486261 - 2¹¹ = 685484213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685486267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342743130 + 342743131.

It is an arithmetic number, because the mean of its divisors is an integer number (342743131).

Almost surely, 2^685486261 is an apocalyptic number.

It is an amenable number.

685486261 is a deficient number, since it is larger than the sum of its proper divisors (1).

685486261 is an equidigital number, since it uses as much as digits as its factorization.

685486261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 552960, while the sum is 46.

The square root of 685486261 is about 26181.7925474938. The cubic root of 685486261 is about 881.7245198836.

The spelling of 685486261 in words is "six hundred eighty-five million, four hundred eighty-six thousand, two hundred sixty-one".