261306061 has 2 divisors, whose sum is σ = 261306062. Its totient is φ = 261306060.

The previous prime is 261306053. The next prime is 261306077. The reversal of 261306061 is 160603162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192515625 + 68790436 = 13875^2 + 8294^2 .

It is a cyclic number.

It is not a de Polignac number, because 261306061 - 2³ = 261306053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261306761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130653030 + 130653031.

It is an arithmetic number, because the mean of its divisors is an integer number (130653031).

Almost surely, 2^261306061 is an apocalyptic number.

It is an amenable number.

261306061 is a deficient number, since it is larger than the sum of its proper divisors (1).

261306061 is an equidigital number, since it uses as much as digits as its factorization.

261306061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 261306061 is about 16164.9639962482. The cubic root of 261306061 is about 639.3173556248.

The spelling of 261306061 in words is "two hundred sixty-one million, three hundred six thousand, sixty-one".