675781 has 2 divisors, whose sum is σ = 675782. Its totient is φ = 675780.

The previous prime is 675751. The next prime is 675797. The reversal of 675781 is 187576.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390625 + 285156 = 625^2 + 534^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-675781 is a prime.

It is a super-2 number, since 2×675781² = 913359919922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (675751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 337890 + 337891.

It is an arithmetic number, because the mean of its divisors is an integer number (337891).

2⁶⁷⁵⁷⁸¹ is an apocalyptic number.

It is an amenable number.

675781 is a deficient number, since it is larger than the sum of its proper divisors (1).

675781 is an equidigital number, since it uses as much as digits as its factorization.

675781 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 675781 is about 822.0590003157. The cubic root of 675781 is about 87.7543510747.

The spelling of 675781 in words is "six hundred seventy-five thousand, seven hundred eighty-one".