771810649 has 2 divisors, whose sum is σ = 771810650. Its totient is φ = 771810648.

The previous prime is 771810631. The next prime is 771810653. The reversal of 771810649 is 946018177.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 656999424 + 114811225 = 25632^2 + 10715^2 .

It is a cyclic number.

It is not a de Polignac number, because 771810649 - 2⁷ = 771810521 is a prime.

It is not a weakly prime, because it can be changed into another prime (771810619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 385905324 + 385905325.

It is an arithmetic number, because the mean of its divisors is an integer number (385905325).

Almost surely, 2^771810649 is an apocalyptic number.

It is an amenable number.

771810649 is a deficient number, since it is larger than the sum of its proper divisors (1).

771810649 is an equidigital number, since it uses as much as digits as its factorization.

771810649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 771810649 is about 27781.4803241296. The cubic root of 771810649 is about 917.2835153626.

The spelling of 771810649 in words is "seven hundred seventy-one million, eight hundred ten thousand, six hundred forty-nine".