771256261 has 2 divisors, whose sum is σ = 771256262. Its totient is φ = 771256260.

The previous prime is 771256259. The next prime is 771256279. The reversal of 771256261 is 162652177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 763472161 + 7784100 = 27631^2 + 2790^2 .

It is a cyclic number.

It is not a de Polignac number, because 771256261 - 2¹ = 771256259 is a prime.

Together with 771256259, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 771256261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (771256061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 385628130 + 385628131.

It is an arithmetic number, because the mean of its divisors is an integer number (385628131).

Almost surely, 2^771256261 is an apocalyptic number.

It is an amenable number.

771256261 is a deficient number, since it is larger than the sum of its proper divisors (1).

771256261 is an equidigital number, since it uses as much as digits as its factorization.

771256261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 37.

The square root of 771256261 is about 27771.5008776983. The cubic root of 771256261 is about 917.0638359281.

The spelling of 771256261 in words is "seven hundred seventy-one million, two hundred fifty-six thousand, two hundred sixty-one".