261090061 has 2 divisors, whose sum is σ = 261090062. Its totient is φ = 261090060.

The previous prime is 261090047. The next prime is 261090083. The reversal of 261090061 is 160090162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 240560100 + 20529961 = 15510^2 + 4531^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261090061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261090461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130545030 + 130545031.

It is an arithmetic number, because the mean of its divisors is an integer number (130545031).

Almost surely, 2^261090061 is an apocalyptic number.

It is an amenable number.

261090061 is a deficient number, since it is larger than the sum of its proper divisors (1).

261090061 is an equidigital number, since it uses as much as digits as its factorization.

261090061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 261090061 is about 16158.2814989714. The cubic root of 261090061 is about 639.1411502258.

The spelling of 261090061 in words is "two hundred sixty-one million, ninety thousand, sixty-one".