261197611 has 2 divisors, whose sum is σ = 261197612. Its totient is φ = 261197610.

The previous prime is 261197549. The next prime is 261197627. The reversal of 261197611 is 116791162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261197611 - 2⁷ = 261197483 is a prime.

It is not a weakly prime, because it can be changed into another prime (261197011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130598805 + 130598806.

It is an arithmetic number, because the mean of its divisors is an integer number (130598806).

Almost surely, 2^261197611 is an apocalyptic number.

261197611 is a deficient number, since it is larger than the sum of its proper divisors (1).

261197611 is an equidigital number, since it uses as much as digits as its factorization.

261197611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 34.

The square root of 261197611 is about 16161.6091711191. The cubic root of 261197611 is about 639.2288979734.

It can be divided in two parts, 26 and 1197611, that multiplied together give a triangular number (31137886 = T₇₈₉₁).

The spelling of 261197611 in words is "two hundred sixty-one million, one hundred ninety-seven thousand, six hundred eleven".