261693317 has 2 divisors, whose sum is σ = 261693318. Its totient is φ = 261693316.

The previous prime is 261693307. The next prime is 261693337. The reversal of 261693317 is 713396162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 233295076 + 28398241 = 15274^2 + 5329^2 .

It is a cyclic number.

It is not a de Polignac number, because 261693317 - 2⁶ = 261693253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261693307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130846658 + 130846659.

It is an arithmetic number, because the mean of its divisors is an integer number (130846659).

Almost surely, 2^261693317 is an apocalyptic number.

It is an amenable number.

261693317 is a deficient number, since it is larger than the sum of its proper divisors (1).

261693317 is an equidigital number, since it uses as much as digits as its factorization.

261693317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 261693317 is about 16176.9378128248. The cubic root of 261693317 is about 639.6330228505.

The spelling of 261693317 in words is "two hundred sixty-one million, six hundred ninety-three thousand, three hundred seventeen".