1855 has 8 divisors (see below), whose sum is σ = 2592. Its totient is φ = 1248.

The previous prime is 1847. The next prime is 1861. The reversal of 1855 is 5581.

1855 = 15² + 16² + ... + 20².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1855 - 2³ = 1847 is a prime.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9 + ... + 61.

It is an arithmetic number, because the mean of its divisors is an integer number (324).

2¹⁸⁵⁵ is an apocalyptic number.

1855 is a deficient number, since it is larger than the sum of its proper divisors (737).

1855 is an equidigital number, since it uses as much as digits as its factorization.

1855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65.

The product of its digits is 200, while the sum is 19.

The square root of 1855 is about 43.0697109347. The cubic root of 1855 is about 12.2870597821.

Multiplying 1855 by its sum of digits (19), we get a triangular number (35245 = T₂₆₅).

It can be divided in two parts, 185 and 5, that added together give a triangular number (190 = T₁₉).

The spelling of 1855 in words is "one thousand, eight hundred fifty-five".