1655 has 4 divisors (see below), whose sum is σ = 1992. Its totient is φ = 1320.

The previous prime is 1637. The next prime is 1657. The reversal of 1655 is 5561.

1655 is nontrivially palindromic in base 12.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5561 = 67 ⋅83.

It is not a de Polignac number, because 1655 - 2⁸ = 1399 is a prime.

It is a Duffinian number.

1655 is an undulating number in base 12.

It is a plaindrome in base 6, base 9 and base 16.

It is a nialpdrome in base 14 and base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161 + ... + 170.

It is an arithmetic number, because the mean of its divisors is an integer number (498).

1655 is a deficient number, since it is larger than the sum of its proper divisors (337).

1655 is an equidigital number, since it uses as much as digits as its factorization.

1655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336.

The product of its digits is 150, while the sum is 17.

The square root of 1655 is about 40.6816912136. The cubic root of 1655 is about 11.8285814860.

It can be divided in two parts, 1 and 655, that added together give a palindrome (656).

The spelling of 1655 in words is "one thousand, six hundred fifty-five".