775681 has 2 divisors, whose sum is σ = 775682. Its totient is φ = 775680.

The previous prime is 775669. The next prime is 775711. The reversal of 775681 is 186577.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608400 + 167281 = 780^2 + 409^2 .

It is a cyclic number.

It is not a de Polignac number, because 775681 - 2⁷ = 775553 is a prime.

It is a super-2 number, since 2×775681² = 1203362027522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (775601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387840 + 387841.

It is an arithmetic number, because the mean of its divisors is an integer number (387841).

2⁷⁷⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

775681 is a deficient number, since it is larger than the sum of its proper divisors (1).

775681 is an equidigital number, since it uses as much as digits as its factorization.

775681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11760, while the sum is 34.

The square root of 775681 is about 880.7275401621. The cubic root of 775681 is about 91.8814241116.

The spelling of 775681 in words is "seven hundred seventy-five thousand, six hundred eighty-one".