261050551 has 2 divisors, whose sum is σ = 261050552. Its totient is φ = 261050550.

The previous prime is 261050527. The next prime is 261050563. The reversal of 261050551 is 155050162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261050551 - 2⁷ = 261050423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261050591) 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, 130525275 + 130525276.

It is an arithmetic number, because the mean of its divisors is an integer number (130525276).

Almost surely, 2^261050551 is an apocalyptic number.

261050551 is a deficient number, since it is larger than the sum of its proper divisors (1).

261050551 is an equidigital number, since it uses as much as digits as its factorization.

261050551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 261050551 is about 16157.0588598297. The cubic root of 261050551 is about 639.1089088086.

The spelling of 261050551 in words is "two hundred sixty-one million, fifty thousand, five hundred fifty-one".