1775 has 6 divisors (see below), whose sum is σ = 2232. Its totient is φ = 1400.

The previous prime is 1759. The next prime is 1777. The reversal of 1775 is 5771.

It is not a de Polignac number, because 1775 - 2⁴ = 1759 is a prime.

It is a Duffinian number.

It is a plaindrome in base 8 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1777) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11 + ... + 60.

It is an arithmetic number, because the mean of its divisors is an integer number (372).

2¹⁷⁷⁵ is an apocalyptic number.

1775 is a deficient number, since it is larger than the sum of its proper divisors (457).

1775 is an equidigital number, since it uses as much as digits as its factorization.

1775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81 (or 76 counting only the distinct ones).

The product of its digits is 245, while the sum is 20.

The square root of 1775 is about 42.1307488659. The cubic root of 1775 is about 12.1078245500.

It can be divided in two parts, 17 and 75, that multiplied together give a triangular number (1275 = T₅₀).

The spelling of 1775 in words is "one thousand, seven hundred seventy-five".