261262591 has 2 divisors, whose sum is σ = 261262592. Its totient is φ = 261262590.

The previous prime is 261262577. The next prime is 261262607. The reversal of 261262591 is 195262162.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261262591 - 2¹¹ = 261260543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261262541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130631295 + 130631296.

It is an arithmetic number, because the mean of its divisors is an integer number (130631296).

Almost surely, 2^261262591 is an apocalyptic number.

261262591 is a deficient number, since it is larger than the sum of its proper divisors (1).

261262591 is an equidigital number, since it uses as much as digits as its factorization.

261262591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 34.

The square root of 261262591 is about 16163.6193657238. The cubic root of 261262591 is about 639.2819020949.

The spelling of 261262591 in words is "two hundred sixty-one million, two hundred sixty-two thousand, five hundred ninety-one".